272 AMERICAN JOURNAL 



that some of the views here brought forward may prove ill- 

 founded ; yet, if their publication incites some naturalist (more 

 favorably situated than myself for examination of the living 

 animal) to give to the world a thorough monograph of any spe- 

 cies of the order, I shall not regret their refutation. In any 

 case, I would urge most strongly on all observers the duty of 

 doing what they can to dispel the prevalent uncertainty in regard 

 to the questions alluded to, which have too long demanded investi- 

 gation, yet failed to obtain it. 



Patella pentagona, (Born.), Rve. Plate 15 fig. 22. 



Patella 'pentagona, (Born. Mus. t. Vindobonensis, pi. 15, f. 4, 



5). Rve. Conch. Icon. pi. xx, f. 48, a, b, c, 1854. 

 Patella stelkeformis, Rve., Conch. Systematica. 

 Patella cretacea, Rve., Conch. Icon. pi. xxi, f. 53, a, b. 

 Patella tramoserica^ A. Adams, (? Chemn., not of authors),. 



Annals Nat. Hist., ii, 1868, p. 369. 

 Patella paumotensis, Gld., Proc. B. S. N. H. ii, p. 150,1846. 

 Expedition Shells, 8, Moll. U. S. Ex." Ex. p. 339, fig. 

 MO-a to e. 

 Animal with the foot gamboge yellow, remainder of the body 

 pale yellow ; muzzle reddish; cirri of the mantle opaque white.* 

 Foot large ; mantle margin narrow, cirri disposed in twenty-four 

 clusters of five each, two short ones arising from the margin, 

 two rather longer from the inner mantle-edge, and between these 

 a fifth twice as large as the others. Head slender, produced. 

 Branchige smaller in front, but not interrupted ; tentacles moder- 

 ate, slender. Anal, infra-anal and renal orifices well defined, 

 small, short, but prominent. Formula, ^! 



Hah. Society Islands, Garrett. Paumotu Islands, Tahiti, Gld. 



The dentition of this species allies it with the typical patellas 

 of the type of P. vulgata ; the branchiae are similar ; not inter- 

 rupted in front, as Mr. Couthouy says, but continuous, as they 

 are figured in the plates of the Ex. Exp. 



Genus PATINELLA.f 



Shell solid, porcellanous, with an erect subcentral apex. Cor- 

 don complete, equal all around ; sides of foot provided with scal- 

 loped lappets. Teeth, " Inner uncinus plate-like, with- 



OHt a cusp. Second lateral the largest. 



* Couthouy MSS. 



t From Patina, a dish. 



