196 MR. BRODERIP’S DESCRIPTIONS OF SOME 
The philosophical view which M. Lesson has taken of this subject is entirely con- 
firmed, as far as regards the anatomical part of it, by Mr. Owen, who gives me the 
following result of his investigations founded on the dissection of Mr. Cuming’s speci- 
mens. ‘‘ The soft parts of Crepidula,” says Mr. Owen, ‘‘ are the same with those of 
Calyptrea in all essential points of structure, differing only in the proportionate extent 
of the anterior part of the foot, and dorsal groove of the mantle.” The truth of the 
observation on the gradations of form of the inner chamber will strike every zoologist 
who views Mr. Cuming’s extensive collection; and it should be recollected that 
M. Lesson came to this conclusion from the study of materials comparatively slender. 
As the memoir of M. Lesson must deservedly become a leading authority on this 
family of Gasteropods, it becomes the more necessary to point out an error of the 
draftsman, which, as I do not find that M. Lesson has observed upon it, may probably 
have escaped that gentleman’s notice. In the figure of Calyptrea (Crepipatella) Adolphei', 
the position of the head of the animal is wrong ; its real situation is nearly opposite to 
the point which it occupies in M. Lesson’s plate. I have, in company with Mr. Owen, 
examined many specimens, and there are some yet undisturbed in the Museum of the 
Royal College of Surgeons in London which leave no doubt on this subject ; indeed, it 
would be contrary to all analogy and the general rules of animal mechanism were the 
fact otherwise. The position of the head in M. Deshayes’s plate is correct. 
CALYPTRAID A. 
Subgenus Catyprrza. 
Testa subconica, subacuminata, cyathi basi adherente, lateribus liberis. 
a. Cyatho integro. 
1. CaLypTRHA RUDIS. 
Tab. XXVII. Fig. 1. 
Cal. testa fuscd, subdepressd, suborbiculari, radiatim corrugatd ; limbo crenato ; cyatho con- 
centrice lineato, albido, irrequlariter subcirculart ; epidermide subfuscd. 
Diam. 2 poll., alt. 2. 
Hab. in America Centrali. (Panama and Real Llejos.) 
This species, whose white onyx-like cup, adhering only by its base, shows to great 
advantage against the ruddy brown which is the general colour of the inside of the 
protecting shell, was found under stones. The young shells are the flattest and most 
regular in form, but their inside is generally of a dirty white dimly spotted with brown. 
The measurement is taken from the largest specimens. 
' Zoologie de la Coquille, Atlas, Mollusques, Pl. 15. fig. 2. A. 
