420 BALANIDJE. 



I have seen eight specimens of this form — two in Mr. 

 Cuming's collection, one of which was procured at Iquique 

 in Peru, the other from an unknown locality ; one was given 

 me in Chile, and was stated to have come from the Pacific; 

 two others are in Mr. Stutchbury's collection, from un- 

 known but distinct localities, and three in a group in the 

 British Museum. These eight specimens, of which six were 

 collected separately, all strikingly agree in general aspect 

 and in details of structure, so that I can easily recognise the 

 shell, and can at once pick out a single compartment, when 

 mingled with those of the two foregoing species ; neverthe- 

 less, the differences are so small, that I at first hesitated 

 whether to name the species; but, upon reflection, I am 

 convinced that it is distinct. Coro?nda regince is much 

 more closelv related to C. diadema than to C. balcenaris, 

 and I suspect that it replaces in the Pacific the former of 

 these two species. 



General Appearance ; shell conical, straight-sided ; some specimens 

 being nearly as much depressed as C. balcenaris, and considerably more 

 depressed than any variety of C. diadema; other specimens being 

 globulo-conical, but rather less globular than the ordinary form of C. 

 diadema. I may here remark, that shape is of more value in this 

 genus, in which the shell is attached to the yielding skin of whales, 

 than in those genera in which it adheres to rocks. The orifice is neatly 

 hexagonal, and the w r hole internal cavity, when the opercular mem- 

 brane is removed, can be seen from one point of view, owing to the 

 contraction of the lower part of the cavity and small size of the basal 

 membrane. The surface of the shell is smooth, but has, even up to 

 the summit, a peculiar frosted appearance, different from that of the 

 foregoing species, caused by the longitudinal striae being rather more 

 distinct, and being crossed by beaded, very delicate transverse lines of 

 growth. The ends of the transverse loops, forming the exterior sur- 

 faces of the compartments, are much flattened, even more so than in 

 C. balcenaris. The lines of junction between the loops, are finely 

 serrated, as in C. diadema; and internally they are solidly filled up, 

 instead of being formed into a set of tubes by longitudinal septa, as in 

 C. balcenaris. The under side of the shell, with its folded walls, pre- 

 sents an appearance intermediate between the variable appearance of 

 this part in the above two species. 



The sutural edges of the radii (PI. 16, fig. 4) offer by far the most 

 remarkable character, in their thinness from top to bottom ; for they 

 hardly exceed one fifth of the thickness of the compartment, measured 

 from the external surface to the base of the sheath ; hence a verv larce 

 cavity is left between the radii and alae : in the thickness of the radii 

 the three species already described form a series, C. reyince at one 



