Fig-shells.- JIOLI-USCA.- 



-R<KK-=^IIEI LS. 



323 



eelves; and of late, conchological systematists have 

 made various alterations in it. 



This family, as now constituted, contains those 

 species, the animals of which have the siphon of the 

 mantle and the canal of the shell long and straight, 

 and the foot simple in front. The shell is spiral in 

 form or pear-shaped, the pillar or culumella smooth, 

 the spire short, and the outer lip generally thin. The 

 operculum is not always present, but when it does 

 occur, it is of an ovate figure, small in size, and 

 acute or claw-shaped. The species are not numerous, 

 but many of thera are of considerable size, as the 

 Fyrula {Casskhdus) patula, from Panama, on the 

 western coast of America, a rather ponderous shell 

 with a large, ovate, expanded mouth, a broad, straight, 

 open canal, and a very short spire ; the Fitsus [Cussi- 

 dulus) colosseus of Lamarck with a very long canal, a 

 rounded form, generally covered with a rough, strong, 

 epidermis, and as its name imports, of considerable 

 magnitude, being indeed one of the largest species 

 of the sub-order to which it belongs. They are 

 natives of tropical seas, and the animals oi iwttda and 

 mehngena, the one found on the mud banks of Panama, 

 and the other in Jamaica, are used by the natives as 

 food. Some of the species, especially those belonging 

 to the sub-genus Fulgur, are reversed shells, that is, 

 the whirls turn from right to left, and the mouth is on 

 the left side of the axis when the shell is in its natural 

 oosition. 



Family II.— MUPJCID.^^ [Rod-shelh). 



The family of llock-shc^Ils is the next in order. 

 This is a very numerous famil}', and contftiiis many 

 of the largest and most beautiful shells that adorn 

 our cabinets; shells remarkable alike for the delicacy 

 of their sculpture and variety of colours with which 

 they are endowed. The animals have the mantle 

 inclosed, and the margin produces ridges or varices 

 at intervals across the shell, becoming extended in 

 fi'ont, and forming a straight, more or less elongate, 

 siphon. The shell is spiral, often turreted, more or less 

 extended at the fore part into a straight siphonal canal ; 

 and the columella or pillar is smooth. The operculum 

 is horny, annular, and has the nucleus apical or sub- 

 apical. 



The ROCK-SHELLS, geiuis Murex of Linnsus, origi- 

 nally contained a great many species which are now 

 referred to several distinct genera. De Blainville and 

 Lamarck separated many of these, and since their time 

 others have been removed altogether, while several have 

 been formed into sub-genera or groups. The recent or 

 living species are numerous and are world-wide in their 

 distribution, being most abundant on the west coast of 

 tropical America, and occur also in numbers in China, 

 Africa, and the West Indies. They are in general 

 handsome shells, and are remarkable for having the 

 whirls ornamented with three or more continuous, longi- 

 tudinal ridges or varices, secreted by the margin of the 

 numtle, as already stated, and generally formed on the 

 completion of about a third of a whirl annually.* These 



• The animal, at certain periods of its growth, exp.-inds the 

 ed^j'C of its mantle, and during this time deposits appendages 



varices are sometimes rounded or sjiinous, at others they 

 are branched or foliaceous, and in some species again 

 they are lamellar. The aperture is generally ovate, 

 and in some species is contracted in front into a long, 

 narrow, tubular canal, in others into a moderate or 

 short canal, recurved or bent up to the right, often 

 partly closed, and occasionally tubular. The oper- 

 culum is ovate, with the nucleus sub-apical, within the 

 apex. Among the species which have the rounded 

 or spinous varices, and the long tubular canal forming 

 the restricted genus Mtirex, we may mention the 

 Murex cormUus of the Indian seas, commonly known 

 by the name of Hercules' Club, a prettily marked shell 

 about seven inches in length ; the il/. brandaris, a 

 native of the shores of the Mediterranean, and which is 

 often used by the Neapolitans as an aiticle of food ; 

 and the M. crassisjnna and temiispiim, well known 

 to collectors by their names of the Thorny Woodcock 

 and Snipe ; names derived from their long and slender 

 canals or beaks ; the latter also, from its numerous 

 regularly arranged spines, being known to collectois 

 by the name of Venus' Comb. Among those specii'S 

 which have the varices garnished with jdaited leaves 

 torn or divided into branches (foliaceous), and the 

 canal moderate or short and recurved (I'ornnng the 



Miirex (Chicoreas^ iiiflatus- 



genus Chieoreus or Endive-leaf rock-shells), we find 

 the varices vary in number, being generally either three 

 or six, though sometimes more. In those which hav e 

 only three branched varices, there is on each of tlie 

 alternate divisions of the shell a more or less well - 



on the edge of ita mantle for their protection ; these expansions 

 ot' the mantle are then gradually withdrawn, and the portion of 

 Ihe shell which the animal forms between this time and llie 

 next development of the appenJa^^es, is of the common shape; 

 but the expansions produced for their protection are left on tlie 

 surface of the shell, fonning variously shaped bands across tlie 

 whirls, which have been called varices, from some of them 

 looldng lilie dilated veins ; these varices and the snines ujion 

 them, being formed on the expanded appendages of the maiule, 

 exactly correspond to them in form, and afi'ord good charac' 

 ters for the determination of the groups and species. — Gray, 

 Si/no2isis of British Museum, 18-12, 



