AKT. 1!) XEW SPECIES OF MOLLUSKS^ DALL. S 



A number of specimens were obtained. Tlie animal evidently 

 prefers to settle on a spiral shell, probably one with a band near the 

 suture like a Terehra, which would account for tlie impressed right 

 side. The margins are not crenulate, in spite of the sculpture, which 

 may be a normal character of the species. The coloration is uniform 

 in all the specimens, and quite imlike any other Crepidula known 

 from the western Atlantic. There is a variable concavity under the 

 apex which usually is feeble or obsolete. 



ACMAEA PULCHERRIMA (Ouilding MS), new sp«iies 



Patella pulcherriiaa " Guilding," Beau, Jouni. de Coiichji., vol. 2, p. 426, 1851; 



Cat. coq. Guadeloupe, p. 19, 1858 — Petit, Journ. de CouchyL, vol. 5, p. 155, 



1856.— Pfeiffek, Mai. Blatt, vol. 4, p. 27, 1857.— Krebs, W. I. Marine 



Shells, p. 89, 1864. (Name only in each case.) 

 Patella candc.ana Petit, Journ. de Conchyl., vol. 5, p. 155, 1856, not of Orhigny. 

 Acmaea punctulata (Gmelin), var. pulchcrrima Pii,sriRY, Man. Conch., vol. IH, p. 



38, 1891. 



For three-quarters of a century the name of this species has appeared 

 in the literature, due probably to the distribution of named spec- 

 imens by Guilding; but neither Doctor Pilsbry nor myself has been 

 able to discover any published description or figure. In revising the 

 collection of east American limpets in the National Museum many 

 hundreds of this form were found from widely distributed localities. 

 Though nearest to certain varieties of -4. punctulata (hybrids?), as 

 indicated by Doctor Pilsbry, it seems worthy of specific rank. 



Shell small, depressed, thin, usually with a glassy surface, the apex 

 slightly in front of the center of the shell, the margin entire; sculp- 

 ture of the surface when fully developed of fine numerous, subequal, 

 not dichotomous, low riblets finely imbricated by numerous low 

 sharp concentric lamellae; these are usually worn off or absent on 

 beach specimens; the color of the shell is pinkish, either suffused or 

 in obscure rays, sometimes broken into dots; the interior whitish, 

 with, in fully adult specimens, a narrow pinkish brown margin; length 

 of shell, 16; apex to anterior margin, 7; width, 11 ; height, 4 mm. U. 

 S. Nat. Mus. Cat. No. 250071. 



The specimen selected as type is from St. Thomas, West Indies, 

 collected by Maurice Petit. The species is connnon throughout 

 the Antilles and south Florida. 



UOTIA (UPPISTES) TORTUGANA, new spteies 



Shell small, planorboid, white, with about three whorls; spire llat- 

 ened, base with a wide funicular umbilicus; whorls with a strong carina 

 above and below the periphery and a feeble one midway between them ; 

 there is also a spu-al thread midway between the suture and the pos- 

 terior carina; whorls rapidly enlarging; axial sculpture of equal and 

 at first equally spaced ribs about 20 on the last whorl; these cross 



