OF CONCHOLOGY. 259 



Francisco. It is unlike any species figured or described in the 

 works at my command, and I know of no species with which it 

 might be compared. It belongs to the same group as C. spec- 

 trum, Reeve, as far as the shell goes, but resembles it very 

 slightly. The peculiar spectrum resembles a Chinese character 

 or hieroglyphic, from which I have taken the specific name. 



/Section B ; tvitli two uncini. {? CoUiseUma). 

 CoLLiSELLA SACCHARINA, Linne. Plate 15, fig. 18. 



Patella saccharina, Lin., Syst. Nat. Ed. xii, p. 1258. Ed. 

 Gmel. p. 3695. Lam., An. sans Vert. Ed. Desh. p. 

 527, No. 7. Adams, Chenu, &c. 



Astrolepas, Argenville, Conch, t. 2, fig. M. 



Acmcea saccharina^ Hanley, Wood's Ind. Test. 2d ed. 1856, 

 p. 185, No. 17. 



Patella lanx, Rve., Conch. Icon. pi. xxx, f. 82, 1855. 



? Patelloida stellaris, Quoy and Gaim. (non Rve). 



Mantle edge smooth, narrow, puckered to fit the ribs of the 

 shell. Head small ; muzzle short ; tentacles very small, rapidly 

 tapering to a very sharp point ; hood much produced ; gill stout, 

 moderately large, broad and pointed ; foot oval, thin. Colors 

 yellowish ; sides of foot dark, muzzle blackish, back of head 

 and tentacles nearly white, mantle edge with a mottled dark 

 border. Formula, ^ 



' 2(2~1'1— 2)2' 



llab. Indo-Pacific, Amboyna, Japan. 



My surprise was great when I found this well-known species, 

 which is tabulated as a "■Patella" by the most recent authors, to 

 belong to the Acmseidse ; but it was still further increased when, 

 accidentally referring to that excellent and very accurate work, 

 Hanley's edition of the Index Testaceologicus, I found that Mr. 

 Hanley had anticipated me in the discovery, and it was there 

 referred to the genus Acma^a. 



This and the following species exhibit a peculiarity worthy of 

 notice, in the duplication of the uncinus. For a long time I 

 thought that my eyes were deceived, and that there was but one, 

 which was folded or twisted so as to give the effect of a double 

 cusp, but I found the uncini separated, and lying side by side, 

 after handling the radula, so that I could no longer doubt it. ^ 



CoLLiSELLA BoRNBENSis, Rve. Plate 15, fig. 17, and pi. 17, 

 fig. 38, a, b, c. 



Patella Borneensis, Reeve, Conch. Icon. pi. xxxvi, f. 113, a, b. 



(bad). Identified from specimens. Borneo. 

 Acmoia Bickmorei, Dall, MSS. Amboyna. 



