238 BULLETIN OF THE 



brief diagnosis of Dr. Gould's unfigured species. Since then I have visited 

 Albany, and examined Dr. Gould's type, which leaves no doubt of their iden- 

 tity. The reception of move material from the Fish Commission and from the 

 Mediterranean enables me to enlarge my description of this species, and to 

 compare it with P. sicula. 



In regard to the shell, it is noteworthy that the spiral nucleus, which, as 

 Gould observed, is always visible, is practically identical in form and sculp- 

 ture with that o^ Simnia, inst described. In fact, Fedicularia would seem to 

 be a form of AmjMperas, modified for the habitat upon a coial, and made 

 irregular by its habitat, as in the case of Ehizocheiliis, etc. From Simnia, 

 living on Gorgonians, to Fedicularia, living on stony corals, is a very short 

 step. The dentition is not dissimilar, and I see no reason for separating 

 Fedicularia from the Amphiperasidce. 



The decussated sculpture is characteristic of the young, and of the period 

 before the animal has permanently settled down to one roost. At the end of 

 this period the margin is usually reflected, thickened, and internally lirate. 

 After this the spiral (or, as the shell stands, vertical) sculpture becomes 

 stronger, the transverse fainter, and the former has a wavy irregularity, while 

 the surface takes on a peculiar faint sagrination, recalling the surface of the 

 coral on which it lives. The largest specimen I have seen — which is 13.0 mm. 

 long by 8.5 from back to base, and 6.0 mm. in maximum width — is suffused 

 toward the aperture with a delicate rosy blush. The sculpture is constantly 

 different from that of P. sicula, which has the revolving threads in the young 

 alternately faint and very strong instead of regularly decussated, has not nearly 

 as many whorls, and has its nucleus always wholly concealed except in the 

 very youngest specimens. The young shell has not the form of Trivia, nor 

 is the columella plicate, as stated by Tryon (Man., VTI. 241). 



In the very large specimen referred to, the mantle margin was thickened 

 and papillose, notched in the middle line behind; the foot oval, rounded be- 

 hind, more pointed in front ; the head small, the tentacles narrow, short, and 

 without eyes or eye pedicels. The cavity of the mantle is very large and deep; 

 there is the ordinary pectinibranch gill stretching across the dome of this cav- 

 ity, with the anal papilla at its distal extreme on the left side of the head. 

 AVhat would seem to be the sexual papilla, large, prominent, globulose, is situ- 

 ated at the other extreme on the right, almost as far back as the posterior end 

 of the foot. The soft parts make a coil of two whorls. The space upon the 

 branch of coral (generally a Madrepore) where the animal roosts, and the edge 

 of which the aperture of the shell exactly fits, is smoothed away and marginated, 

 looking as if the animal had secreted a pavement, like Capulus, with a centrally 

 situated rougher area. This, however, is not really the case, but the coral has 

 been so eroded as to present much the same appearance, at least w^ith F. sicula, 

 as I have not yet received P. decussata in situ. 



The eggs are very numerous and small. They are impregnated within the 

 ovisac, which, when ready to discharge, seems to comprise a very large per- 

 centage of the total mass of the viscera. In the specimen examined, the young 



