CATOPHRAGMUS, 



In its general form and appearance it closely resembles 

 Octomeris,'' a Genus which we lately thought it our 

 duty to propose^ and, as in that Genus^ the shelly cone 

 immediately surrounding the animal, consists of eight 

 pieces, and its operculum is also composed of four pieces. 

 Here, however, the particular resemblance of the various 

 parts cease, and we have now to describe the peculiarity 

 of our present new Genus. This peculiarity consists in a 

 number of narrow perpendicular valves arranged around 

 the above mentioned shelly cone, and in rows, like pales, 

 the first row of which consists of eight pieces, placed 

 so as exactly to cover the sutures of the shelly cone 

 immediately surrounding the animal; around this are 

 then placed several sets of more and more numerous 

 pieces gradually decreasing in size, so that the outer row 

 which is the most numerous consists also of the smallest 

 pieces. Additional rows seem to be produced as the 

 animal increases in age; for a young specimen in our posses- 

 sion has only one row of eight pieces covering the sutures 

 of the first cone, while a much larger and older specimen 

 still retains part of three rows, and has evidently lost 

 some of the external rows. The young individual also 

 shows that the whole of the pieces are pointed at their 

 superior extremities, whereas, in the old shell these ex- 

 tremities are so worn or eroded as to become very irre- 

 gular and obtuse. The valves of the operculum are also 

 pointed. 



We do not observe any epidermis, though there is 

 probably a very thin one on those parts that are not 

 worn.* 



Two specimens only of this singular Cirripede have 

 come into our possession ; one of these was found in the 

 collection of the late George Humphrey, and the other 

 is attached to a Conia, which we received from Antigua. 



In our plate we have represented, at 



Fig. 1 . The young specimen of its natural size, upon the base of a Conia. 



2. The young specimen magnified. 



3. & 4. Two views of the old shell, natural size. 

 5. & 6. The same views, magnified. 



* We are glad to take this opportunity of correcting an error into which 

 we have fallen, in stating Balanus not to have an epidermis. We believe when 

 in their natural state the shells of that Genus always have a thin horny epi- 

 dermis. 



