21 



HALIDRYS. 



HALIOTID.-E. 



HALIDRYS. [FtJCACEJ!.] 



HA'LIEUS. [PELECANID.E.] 



HALIME'DA, a portiou of the genus Corallina, Linn., for which 

 Lamarck had used the name Plabellaria, is thus styled by Lamouroux. 

 (' Exposition Me"thodique des Genres.') The articulations are flat or 

 compressed, rarely cylindrical, almost always flabelliform ; the axis 

 fibrous, surrounded by a thin cretaceous substance. 



HALIMUS. [MAIADJS.] 



HALIOTID^E, a family of Gasteropodous Mottusca, to which the 

 shells commonly called Ear-Shells, or Sea-Ears, belong. Mr. Swain- 

 son, in his first series of ' Zoological Illustrations," observes, when 

 writing on the Small-Holed Californian Ear-Shell (Ifaliotii Califor- 

 niftuu, 1820-21), that "the definitions given by conchologists up to that 

 time were so imperfect that they had left our knowledge of these 

 shells nearly the same as in the time of Linnaeus. Seventeen species 

 only are enumerated in Mr. Dillwyn'a work ; although thirty-four have 

 fallen within iny own observation during the last few months." 



Linnaeus, who records the saven species known to him under the 

 generic appellation of Ifa/iotis (Sea-Ear), describes the animal as a 

 Slug (Umax), and the Shell as ear-shaped and open (patens), with a 

 lateral hidden spire, and the disc longitudinally pierced with holes 

 (poris). He places the genus between Nerita and Patella. 



Cuvier, in the first edition of his ' Regne Animal' (1817), makes the 

 Ormiers (Haliotif of Linnaeus) the first genus of his sixth order of 

 Gastropods, Scutibranchiata. [GASTEROPODA.] He observes that it is 

 the only genus of the order which has its shell turbinated, and that 

 among these sort of shells that of the Ormiers is remarkable for the 

 excessive amplitude of its aperture, its flatness, and the smallnens of 

 the spire, which is seen from within. This form, he adds, has caused 

 it to be compared to the ear of a quadruped. Cuvier divides the 

 genus into the following sub-genera: 1, the Haliotids, properly so 

 called (Uatiotit of Lamarck) ; 2, the Padolli of De Montfort ; 3, the 

 StoinaJiie of Lamarck. The Ormiers are immediately followed by the 

 Cabochons (Capuliu of De Montfort Patella Hunyarica). 



Lamarck (' Animaux sans Vertcbres," 1817) arranges the genus 

 Jfaliotit, which is immediately preceded by Stomatia, as the last genus 

 of his Macrostomeg. The following is his definition of Jlalwtis : 



" Shell ear-shaped, most frequently flattened ; with a very short 

 spire, sometimes depressed, nearly lateral. Aperture very ample, 

 longer than it is wide, entire in its perfect state. Disc pierced with 

 holes disposed on a parallel line near the left-hand border, the last 

 commencing with a notch." 



The same zoologist makes the following observations on .the genus 

 as restricted by him : " The Haliotids constitute a very beautiful 

 genus, rather numerous in species and remarkable for the singular 

 form and the brilliant nacre of their shell. They have received the 

 name of Sea-Ears, because they in fact represent sufficiently well the 

 form of the cartilage of the car in man. Their shell is an oval-oblong, 

 flattened in general, slightly spiral near one of its extremities, and 

 furnished with a row of holes disposed on a curved line near the left- 

 hand border and parallel to it As the animal increases in growth, it 

 forms for itself a new hole on the edge of the anterior part of the 

 shell ; this hole commences with a notch which serves to give a 

 passage to the siphon of the animal, and is afterwards completed ; 

 when another is formed posteriorly. In its natural situation, and 

 when the animal crawls, this shell may be considered as a reversed 

 basin with its convexity upwards. Its circumference is then con- 

 siderably exceeded by the very large foot of the animal, and the spire 

 i found on the posterior part of its body. Following the description 

 of the Ormier (the animal of the Jfaliutis) given by Adanson, I had 

 supposed that the branchiae of this animal were exterior, like those 

 of tin: Phyllidians : but M. Cuvier has undeceived me by showing me 

 iiey are hidden in a particular cavity. Ilaliutii therefore belongs 

 to the family of Macrostomes. With regard to the tentacula, it has 

 not perhaps really more than two. But as it is not uncommon (assez 

 fivqnent) among the marine Trachelipods to find the eyes carried each 

 upon a tubercle which springs at the external or posterior base of the 

 tentacula, these tubercles are apparently more elongated here than 

 elsewhere : in this case the two larger tentacles are the anterior ones." 

 Lamarck records fifteen species, including llaliotis dn/>in. 



Mr. Swainson (' Zoo!. Illustr.,' 1st series) remarks that " the genus 

 Padollut of Montford (De Montfort ?) resting entirely on the uneven- 

 ness of the outer lip, without any knowledge of the animal," appears 

 to him an unnecessary distinction, for such, he observes, is the cha- 

 racter of all young shells, and also of mature ones, whose outer 

 surface is rtig'jgwi or uneven. 



De Montfort (1810) gives the following generic characters for 

 Padalliui : Shell free, univalve, in the form of an ear, pierced with 

 one or two holes ; summit spiral, flattened, dorsal ; aperture oval, 

 wide open ((^vasee), entire, perpendicular; left lip reflected and 

 trenchant ', back covered with an epidermis, having a gutter in the 

 middle and in the direction of the spire. He gives as the type of the 

 genus Padolhu rttliictmdia, and proceeds nearly as follows : ' In 

 arranging this shell as intermediate between the Kigareti the Stomatia; 

 andt ; ,],.,. that we have been able to extahlixh 



upon it, a ':.- Hi-Tim. Sufficiently similar to the llaliotidet by its 



. it, js in Home manner 

 nevertheless approximated to the Stomatia:, inasmuch as it has very 



few holes ; but it presents, more than almost any of these shells, a 

 spiral gutter, hollow in the interior, elevated on the back, placed in 

 the middle and curved in the direction of the spire. This hollow, or 

 gutter, is independent of the curved and serial line of holes, which 

 are nearly all obliterated. The right- lip is also more opened out 

 (s'^panouit aussi d'avantage), it juts out and festoons (festonue) over 

 the left lip towards the summit, and to the height of the spire : the 

 interior offers an iridescent and undulated nacre. Externally it is of 

 a brick-red, and the summit, in consequence of losing its exterior 

 calcareous and coloured coat, is nacreous. The back is finely striated 

 and reticulated, and the successive periods of growth are very strongly 

 marked there. There is no doubt that the obliteration of the holes 

 of the Padolli are a consequence of the absence of some organs, with 

 which the Haliotidet must be eminently provided, and it is even 

 probable that the single hole which notches their border serves during 

 the life of these mollusks to lodge a fold of the border of the mantle, 

 rolled into a tube and serving for respiration ; a tube which we shall 

 find among many of the spirivalve mollusks." 



Considering the time at which De Montfort wrote, there is much 

 good reasoning in this passage ; it rnnst be recollected that he evi- 

 dently gave his descriptioa from a young shell ; for he says in the 

 course of it that the shell sometimes reaches more than an inch in 

 its greatest diameter. 



Dr. Leach (1814) adopted De Montfort's distinction and name. The 

 doctor says that this genus is readily distinguished from Ifaliotin 

 (Ear-Shell) by the irregular form of the outer edge or lip ; the disc, 

 he adds, has fewer perforations and the spire is placed farther on tho 

 back. He states in conclusion that the animal is unknown, but is 

 probably not very unlike that of the Ear-Shell. 



Mr. G. B. Sowerby (' Genera of Recent and Fossil Shells '), 

 observes, that with the exception of a few that are commonly known 

 by collectors and Linnreans as Imperforate Ear-Shells, the genus 

 Ilaliotit has not suffered any dismemberments. " An attempt," con- 

 tinues Mr. Sowerby, " has indeed been made by Moutfort to separate 

 from the genuine llaliotidei two or three species under the name of 

 Padottiu, in which ha has been followed by Leach, but as fur as 

 respects general adoption this attempt appears to have been as unsuc- 

 cessful as it was unnecessary. Not so the separation of the Imper- 

 forate Haliotido, which are easily distinguished by wanting the row 

 of perforations so very characteristic of the true Haliotix." 



The Otidta form the first family of Sculibi-anchiata, the third order 

 of Paracep/ialop/iora Ilenmaphroddam M. De Blainville'a arrangement 

 (' Manuel de Malacologie," 1825.) The first genus of this family is 

 Iliili'itii, divided into four sections, and including the genera Padullus 

 and Stomatia. 



M. Rang (' Manuel," 1829) continues the Ormiers (Macrostomes of 

 Lamarck, Otidta of De Blainville, Auriformes of Latreille) as the first 

 family of Scutibranchiata (Cuvier) ; but he makes it consist but of one 

 genus, JIaliotit (Linnaeus). The genus Stomatia of Lamarck he places 

 under the Sigarets of De Fdrussac, as well as the genus StomateUa of 

 Lamarck, which he seems to consider as including the Padollus of 

 De Montfort. The Sigarets in this arrangement are made to form the 

 ninth family of the Pectinibranchiata of Cuvier. 



In Cuvier's last edition of the ' Rfegne Animal ' (1830), the position 

 and arrangement of the Ormiers remains as in the first edition, with 

 the exception that in the last edition the Scutibranchiata form tue 

 eighth order of his Gastropods. 



In the present state of our information it will perhaps be as well 

 to select the arrangement proposed by Cuvier, and in great measure 

 adopted by M. De Blaiuville. M. Rang, in his description both of 

 ttomatella (including Padollus) and Stomatia, says, " Auimal 

 unknown." 



llaliL'it (properly so called; Haliotii, Lamarck). Animal. One of 

 the most ornamented of Gastropods. All round its foot to its moutli 

 there is, at least in the more common species, a double membrane cut 

 out into leaflets (feuillages), and furnished with a double row of fila- 

 ments. On the outside of its long tentacles are two cylindrical 

 pedicles for carrying the eyes. The mantle ia deeply divided on the 

 right side, and the water, which passe* by means of the holes in tho 

 shell, can, through this slit, penetrate into the branchial cavity ; along 

 its edges again are also three or four filaments, which the animal can 

 also cause to come out through these holes. The mouth is a short 

 proboscis. (Cuvier's description for all Gmelin's JIaliotide, except 

 //. imper/orata and //. perverta.) Body oval, very much depressed, 

 hardly spiral behind, provided with a large foot doubly fringed on its 

 circumference. Head depressed ; tentacles a' little flattened, joined 

 (connds) at the base ; eyes carried on the summit of prismatic pedun- 

 cles, situated on the external side of the tentacles. Mantle very deli- 

 cate, deeply divided on the left side ; the two lobes pointed, forming 

 by their junction a sort of canal for conducting the water into the 

 branchial cavity situated on the left, and inclosing two very long, 

 uiic-.|ual, pectinated branchiae (peignes branchiaux). (De Blainville.) 



Animal oblong, depressed, furnished with a large head anil a. short ' 

 proboscis, at the extremity of which is the mouth, containing a tongue 

 armed with points (aiguillons) ; tentacles two, long and cylindrical ; 

 eyes on pedicles, implanted at their external base, a little backwards. 

 Mantle short, delicate ; foot very large, oblong, furnished all round 

 with a double row of festoons agreeably cut out or pinked (decoupiS*). 



