114 Mr. W. Clark on the Muricidse. 



our descriptions of the M. efinaceus, M. lapillus, M. undatus, or 

 any other in our list, which will furnish every essential generic 

 character ; aiid I fully expect to have it in my powei", by the exa- 

 mination of live M. Islandicus, to show the correctness of their 

 assigned position as members of the genus Murex. I can say 

 nothing of the animal of M. trichotropis, which is admitted here 

 as probably belonging to this section. 



Murex et Buccinum, Linnseus. 

 Sectio III. 

 Testa inflata, varicosa, vel Isevis, ssepe spiraliter granoso-un- 

 dato-striata. Canalis brevis. Apertura ovalis. Columella fas- 

 tigiata. Operculum corneum. 



Murex undatus, nobis. 

 Buccinum undatum, Linnaeus et auctorum. 

 Animal with eight s])iral turns, of a pale yellow ground colour 

 in all parts, sparingly interspersed with irregular dark blotches on 

 the upper part of the foot, the tentacula, and branchial fold ; the 

 mantle is of thin texture, and no portion of it extends beyond 

 the shell, except the branchial fold, which floats when in action 

 far beyond the emargination of the shell, for only slight traces 

 of a canal remains; the head is small, compressed, not at all 

 produced, and does not in the least interfere with the coalition 

 of the tentacula at their bases ; they are long and flattish, broad 

 at their origins as far as the eyes, which are placed on shortish 

 external offsets, and the remaining portion terminates in rounded 

 but not pointed extremities ; the mouth is a vertical central 

 fissure rather below the surface of the head, and from it a very 

 long and powerful pi-oboscis is exserted, armed with the usual 

 spinous tongue. The foot is large, broad, and about as long as 

 the shell, slightly auricled and curved in front, and rounded pos- 

 teriorly to an obtuse point ; on its upper part it carries a com- 

 paratively small, but strong, light corneous suboval operculum, 

 having the striae of increment of the same form, with the nucleus 

 about the middle of its outer edge. There are two branchial 

 plumes, one very large and pale brown, the other small, linear, 

 of a still darker brown. We say nothing of the internal organs, 

 as it has already been stated that they are identical throughout 

 the Muricidal tribe. We refer those who are desirous to see a 

 full account of the internal structure of this animal to Baron 

 Cuvier's anatomies, where they will find an elaborate account 

 and delineation of it. This celebrated animal may be looked on 

 with perfect confidence as a faithful type of the entire Muricidal 

 division ; our descrii^tive notes of the various animals will fully 

 confirm this view. 



