116 Mr. W, Clark on <Ae Muricidse. 



cate and aui-icled in front, somewhat attenuated in the middle, 

 and has a rounded termination, with, on its posterior upper sur- 

 face, an irregular oblong, red-bro^vn, corneous, subunguiculated 

 operculum, having the lines of increment raised on the inner 

 surface. The buccal mass, as in all the Murices, hes within 

 the proboscis, which itself is inclosed in a case, and consists of 

 two pale fleshy lobes, supported by very thin corneous plates, 

 between which the tongue is fixed, and after passing the extent 

 of the proboscidal tube it forms a coil of four or five turns imme- 

 diately behind its posterior part ; it is narrow, white and spiny, 

 and about half an inch long ; under the coil is the cerebral cor- 

 don embracing the oesophagus, fonned of about eight suboval 

 yellow ganglions. There are two branchial plumes, one large 

 and pale brown, the other minute, linear, and of a much darker 

 hue ; they have the arterial vein in the centre, and are fixed as in 

 its congeners ; then are seen the mucous fillets which furnish the 

 material for the capsules of the ova ; the rectum and ovarium, 

 with the canal of the \dscous sac, debouche on the right side. 

 The stomach is enormous, and always found filled with a tena- 

 cious mass of pulp ; the ovarium is yellowish white, mixed up with 

 the liver, which is of a dark brown green, occupying with either 

 the ovarium or testis the posterior whorls of the shell to the apex. 

 The sexes are distinct j the male organe generateur differs from 

 the ridged, grooved, spatulate and double-pointed appendages of 

 some of the Murices, in being smaller, flatter, less pointed and 

 more strap-shaped. This detailed account of these organs will 

 not be repeated, as they are essentially the same in all the 

 Murices. 



This section I believe contains only the British species now 

 described. It is common everywhere, and rarely extends its 

 habitat beyond the littoral zone. 



Miirex et Buccinum, Linnaeus. 



Sectio V. 

 Testa tumida, granuloso-plicata, vel Isevis. Canalis obliquo- 

 dorsali-brevissimus. Apertura ovalis. Columella striata, in pli- 

 cam iutorta. Operculum corneum. 



Murex reticulatus, nobis. 

 Buccinum reticulatum, Montagu. 

 Kassa reticulata, Lamarck et auctorum. 



Animal spiral ; mantle of very thin texture, not extending be- 

 yond the aperture, except that portion of it styled the branchial 

 fold, which in adult specimens is often exserted an inch beyond 

 the emargination of the shell ; it floats free, as there is no canal 

 for its support ; it is also evidently a tentacular aid. 



