Harfshells.] 



MUSEUM OF ANIMATED NATURE. 



235 



Jess rare and costly than (he Harpa imperialis ; all 

 the species, however, are depressed in value now, to 

 what they were some few years since. i 



It is a remarkable circumstance, of the truth of j 

 which we are assured by MM. Qiioy and Gaimard, 

 and also by M. Heynaud, that when suddenly 

 alarmed or threatened with instant danger, the mol- 

 lusk forcibly draws itself up into the recesses of its 

 shell, disembarrassing itself of the posterior part of 

 the foot, which, according to M. Reynaud, being 

 loo voluminous to be retracted within the shell, 

 suffers amputation from the edge, against which it is 

 forced by the contractile action of the muscular 

 system. 



It would be very interesting to know whether, as 

 is most probable, the part thus cut off becomes 

 renewed ; and whether the moUusk has been ob- 

 served to act thus not only when caught and roughly 

 handled by man, but when alarmed under the water 

 by other enemies. 



We l)clieve that only about two species of fossil 

 Harpa have been discovered, both in some of the 

 tertiary formations near Paris. 



We may now turn to the genus Dolium. In this 

 genus the shell is light and delicate, of a somewhat 

 globular figure, with a large aperture, and a twisted 

 columellar lip. The ]a.st whorl forms nearly the 

 whole of the shell, the spire of which is small. The 

 right lip is undulated, and the whorls are furrowed 

 externally in the direction of their tournure, or trans- 

 ■sersely to the shell. The operculum is horny. 



2783. — The Helmet Dolhim 

 (Doli'um galea). The Dolium galea is a native of 

 the Mediterranean, but most of the species are 

 found in the warmer seas, and especially those of 

 India. They mostly tenant reefs and beds of rock ; 

 some are of large dimensions. 



Montfort divides this genus into the Tuns (Dolium) 

 and the Partridge Tuns(Perdix). The former have 

 the base of the columella twisted, in the latter it is 

 trenchant. 



According to Cuvier the mollusk has a very large 

 foot expanded anteriorly, a proboscis longer than the 

 shell, and slender tentacles with eyes at the base. 

 He adds, the foot is not provided with an oper- 

 culum. But this appears to be an error. 



The fossil species are limited in number and very 

 rare. Another genus in the present family is Cassi- 

 daria, distinguished by an ovoid ventricose shell, 

 with the spire but little elevated. The aperture is 

 long and rather narrow, and produced anteriorly in 

 the form of a recurved canal ; the outer lip is thick- 

 ened with a fold ; and the columellar lip is covered 

 by a large callosity ; the operculum is horny. 



2784.-^The Spinous Cassidabia 

 (Cassidaiia echinophora). The species of this 

 genus are comparatively limited in numbers. They 

 are widely distributed, but chiefly tenant the warmer 

 seas. The spinous Cassidaria is found in the Mediter- 

 ranean. 



A few fossil species occur in tertiary deposits. 

 From the genus Cassidaria Mr. G. B. Sowerby has 

 separated certain species, upon which he establishes 

 the genus Oniscia. The shell is oblong and sub- 

 cylindrical, with the apex rather obtuse, and the 

 spire short ; the aperture is elongated, and extended 

 into a short canal ; the outer lip is thickened and 

 denticulated within ; the columellar lip is expanded 

 and covered with granules ; externally the shell is 

 tiiberculated or ribbed. Of the mollusk nothing is 

 ascertained. 



2785. — The Cahcellateb Oniscia. 

 {Onisa'a cancellata). We figure this species as an 

 example of the present genus, of which three species 

 are described by Mr. Sowerby from specimens now 

 in the British Museum, but formerly constituting 

 part of Mr. Broderip's noble collection. A fossil 

 species from the tertiary deposits in Italy is recorded, 

 and figured by Mr. Sowerby. Of the habits of the 

 Onisciae little is known, excepting that they are 

 littoral, frequenting banks of sand. 



According to its descrioer the genus Oniscia is 

 intermediate between Cassidaria and Cassis. 



The genus Cassis contains numerous species 

 distinguished by the convexity of the shell, of which 

 the spire is nearly flat, the aperture oblique, narrow, 

 and elongated, with the anterior canal short and 

 recurved ; the right or external lip is thick with a 

 bold reflexion, and is toothed internally; the colu- 

 mellar lip is e.xtensively callous, with long and deep 

 transverse rugse ; the operculum is horny and very 

 small. M. de Blainville divides this genus into two 

 f eclions, thefirst containingthose species which have 

 the aperture long and the outer lip nearly straight ; 

 ihc second containingthose which have the aperture 

 suboval, and the external lip excavated. 



278C. — The Tlherose Cassis 

 (Cassia tubnrosa). This species is an example of M. 

 Ue Blainviile's first section : it is a native of the 

 Vol. II. 



ji West Indian Seas. The lower figure represents the 



\', denuded mollusk of Cassis sulcata. 



I; M. Deshayes enumerates thirty living species be- 

 longing to the genus Cassis, all, with the exception 

 of two or three which are found in the Mediterra- 

 nean, belonging to the hotter latitudes. They tenant 

 beds of sand, ranging from five to ten fathoms in 

 depth. About fifteen fossil species are known, all 

 belonging to tertiary deposits. 



Closely allied to the two preceding forms is the 

 genus Kicinula, which is characterized by M. de 

 Blainville as follows : — The shell is oval, or sub- 

 globular, thick, and beset with points or tubercles ; 

 the spire is very short ; the aperture is narrow and 

 long, with a notch anteriorly ; the right lip is often 

 digitated externally, and toothed within; the co- 

 lumellar lip is callous and toothed or wrinkled : 

 the operculum is horny, oval, and concentrically 

 striated. 



The mollusk very closely resembles that of Buc- 

 cinum. The mantle is provided with a tube, the 

 foot is wide, with appendages anteriorly ; the head 

 is of a semilunar shape, with conical tentacles with 

 the eyes on their outer surface, near the middle. 



M. de Blainville enumerates nine species, all 

 natives of the Indian Seas, where they tenant coral 

 reefs and rocks. M. Deshayes in his tables gives the 

 number of recent species as fourteen, and he also 

 records one fossil species found in the tertiary de- 

 posits near Bordeaux, Dax, and Turin. 



2787. — The Spinous Ricinula 



(^Ricinula lionida). M. de Blainville separates Rici- 

 nula into three sections, of which one is distinguished 

 by the presence of a canal anteriorlyand behind the 

 orifice, the second has no canal and is beset with 

 spines, the third is also destitute of a canal, and is 

 studded with tubercles. The Spinous Ricinula be- 

 longs to the second section. 



We now come to the genus Cancellaria. 



In this genus the shell is oval or globular, thick, 

 and reticulated; the spire is slightly elevated and 

 pointed ; the aperture demi-oval, with a notch or 

 short canal anteriorly ; the right lip is sharp-edged 

 and striated within ; the columella has many plaits 

 or wreaths; the operculum is horny. 



The mollusk is stated to resemble in all essential 

 characters that of Buccinum. 



2788.— The Reticulated Cancellaeia 



{Cancellaria reticulata). The Cancellarise are natives 

 of the seas of the hotter latitudes, where they tenant 

 sandy beds, ranging from seven to sixteen fathoms 

 in depth. M. de Blainville describes twelve recent 

 species, mostly from the Indian and African seas ; 

 and in the ' Proceeds. Zool. Soc' for 1832, p. 50 et 

 seq., will be found the characters of twenty-two new 

 species, brought by Mr. Cuming principally from the 

 Pacific side of Central and South America : one 

 species, the Cancellaria haemastoma, Sowerby, is 

 from the Gallapago Islands ; it is extremely beautiful, 

 nearly white, with a broad dark brown band, and a 

 brilliant orange-coloured mouth. 



The reticulated Cancellaria is found in the South 

 Atlantic Ocean. 



The fossil species of Cancellaria are tolerably 

 numerous. M. Deshayes enumerates forty-two as 

 occurring in tertiary deposits, one of which is 

 identical with a living species. Mr. Lea describes 

 and figures eight additional species from the tertiary 

 formation of Alabama ; he observes that in England 

 the genus has been found only in the London clay, 

 whence three species have been obtained. With 

 respect to the species enumerated by M. Deshayes, 

 he remarks that sixteen are from the Subapennines, 

 the Pliocene of Mr. Lyell, twelve from the Miocene 

 of Bordeaux, five from the Eocene near Paris. 

 Previously to his description of the eight species 

 from Alabama, a single one only had been known 

 as American, viz. the Cancellaria lunata, from the 

 tertiary beds of St. Mary's. 



We now pass to the genus Purpura, so called in 

 allusion to the dye which some of the species afford, 

 and which entered into the composition of the 

 Tyrian purple. The shell is thick, smooth, or 

 tubercular, with a sVort spire, and a dilated aper- 

 ture, and of an oval form, terminated anteriorly by 

 a small notch; the columella is flattened, and ter- 

 minates anteriorly in a point; the right lipissharp, 

 and often thickened and furrowed internally, or pro- 

 duced anteriorly into a conical point. The oper- 

 culum is horny and semicircular. 



With regard to the mollusk, it is elongated and 

 widened in front ; the head is large and furnished 

 with a very short proboscis : there are two conical 

 tentacula, approximated at their base, with the eyes 

 placed on an enlargement near the middle of their 

 external part : the mouth is hidden by the foot, 

 which is ample, considerably advanced anteriorly, 

 with a semilunar marginal outline. 



The Purpurse are very numerous, and widely dis- 

 tributed, principally in tlie warmer seas, a few only 



being European. Most are from the coasts of South 

 America. 



M. de Blainville, who divides the genus into four 

 sections, enumerates fifty species of Purpura, besides 

 five of his section Monoceros. M. Deshayes gives 

 seventy-six species of living Purpura, and six of 

 Monoceros, but to these other species have been 

 added by Mr. Broderip, Mr. Sowerby, and other 

 naturalists, principally from Mr. Cuming's collection. 



2789.— The Pebsian Purpura 



{Purpura Persica). This shell is an example of 

 the patulous section without a tooth at the lip, and 

 with a wide aperture. The accompanying mollusk 

 belongs to the Purpura hasmastoraa. 



2790. — The Imbricated Purpura 

 (Purpura imbricata). Monoceros imbricatum, Lara. 



This species, from South America, is an example 

 of the section Monoceros, in which the right lip 

 near (he notch is armed with a 'conical spine or 

 tooth, pointed, and more or less curved. 



The Purpuras are all littoral in their habits, some 

 tenanting sandy beds, others rocks and reefs, ranging 

 from the surface of the water to twenty-five fathoms 

 in depth. The Purpura lapillus is common on our 

 shores, occurring in great abundance on rocks at 

 low water, and is one of the British mollusks pro- 

 ducing a purple dye, analogous to the purpura of 

 the ancients. 



It must not be supposed that the Tyrian purple of 

 the ancients was a colour similar to that which we 

 now term purple : it approached our scarlet, or at 

 least had in it a tinge of that colour; the most 

 superb hue, according to Pliny, was amethystine, 

 and this was produced by the juice of the Buccinum 

 and Pupura mixed. "Another tint was obtained 

 by saturating astuff, which was at first amethystine, 

 in a bath of the Tyrian purple, so that the dyer tints 

 at first conchylian to facilitate the Tyrian tincture, 

 which then becomes softer and more agreeable." 

 The following observations under the article ' Dye- 

 ing,' in the ' Penny Cyclopaedia,' are very interesting, 

 the more so as they are written by one well ac- 

 quainted with (he modern methods of imparting 

 colour to different stuffs. He says, " In the article 

 'Calico Printing' we have shown from Pliny that 

 the ancient Egyptians cultivated that art with some 

 degree of scientific precision, since they knew the 

 use of mordants, or of those substances which, 

 (hough (hey may impart no colour themselves, yet 

 enable white robes (Candida vela) to absorb colour- 

 ing drugs (colorera sorbentibus medicamentis). 

 Tyre, however, was the nation of antiquity which 

 made dyeing its chief occupation and the staple of 

 its commerce. There is little doubt that purple, the 

 sacred symbol of royal and sacerdotal dignity, was 

 a colour discovered in that city, and that it contri- 

 buted to its opulence and grandeur. Homer marks 

 (he value as well as anliquity of this dye, by de- 

 scribing his heroes as arrayed in purple robes. 

 Purple habits are mentioned among the presents 

 made to Gideon by the Israelites from the spoils of 

 the kings of Midian. 



"The juice employed for communicating this dye 

 was obtained from two different kinds of shell-fish, 

 described by Pliny under the names of purpura and 

 buccinum ; and was extracted from a small vessel, 

 or sac, in their throats, to the amount of only one 

 drop from each animal. A darker and inferior 

 colour was also procured by crushing the whole 

 substance of the buccinum. A certain quantity ot 

 the juice collected from a vast numberof shells, being 

 treated with sea-salt, was allowed to ripen for three 

 days ; after which it was diluted with five times its 

 bulk of water, kept at a moderate heat for six days 

 more, occasionally skimmed to separate the animal 

 membranes, and when thus clarified was applied 

 directly as a dye to white wool, previously prepared 

 for this purpose by the action of lime-water, or of a 

 species of lichen called fucus. Two operations were 

 requisite to communicate the finest Tyrian purple : 

 the first consisted in plunging the wool into the 

 juice of the purpura ; the second, into (hat of the 

 buccinum. Fifty drachms of wool required one 

 hundred of the former liquor, and two hundred of 

 the latter. Sometimes a preliminary tint was given 

 with coccus, the kermes of the present day, and the 

 cloth received merely a finish from the j)recious 

 animal juice. The colours, though probably not 

 nearly so brilliant as (hose producible by our cochi- 

 neal, seem to have been very durable, for Plutarch 

 says, in his ' Life of Alexander' (chap. 36), (hat (he 

 Greeks found in (he (reasury of (he king of Persia a 

 large quantKy of purple cloth, which was as beau- 

 tiful as at first, though it was 190 years old.* 



* " Among other Uiin;j3, tliere was purple of Ilermione (?) 1o tlie 

 amount of live Ihotisand talents." (I'lutarcli's Lives, translated by 

 Lanijiiorne, Wrangliam's edition, vol. v. p. 240.) Horace celebrates 

 tlie Laconian dye in the following lines; — 



Nee I.aconicas mihi 



Trahunt honeslie purpuras clientm. 



C'aitn., lib. ii.,Ode 18. 



2 H 2 



