DOLABRIFERA. 125 



Saint Jeanne de Cayenne (type locality ; Richard) ; St. Thomas, 

 St. Croix (Riise, Oersted, Krebs). 



Aplysia (Dolabella) ascifera RANG, Hist. Nat. Aplys., p. 51, pi. 

 4, f. 7-9. Dolabrifera ascifera MORCH, Mai. Bl., xxii, p. 176. 

 SOWB., Conch. Icon., xvi, pi. 1, f. 6a, 6b. BERGH, Verb. k.-k. zool.- 

 bot. Gesellsch. in Wien., xxii, 1872, p. 441, pi. 5, f. 25-29 ; pi. 6, f. 

 1-10 (anatomy). 



Externally of the same form as D. dolabrifera, but the back is 

 more rounded ; but distinguished by the yellowish-brown color of 

 the surface which is strewn with numerous obtuse projections, like 

 little warts. The dorsal slit is very small, mantle a little larger 

 than in D. dolabrifera. The shell also shows sufficiently recogniz- 

 able differential characters, being wider in the middle, more angular, 

 and especially thicker in the center, which is calloused and enamel- 

 led ; the apex is more calloused and quite small. This shell is the 

 most calcareous of the genus. It is perfectly white. 



Figures 19, 20, 29 are from the original illustrations of Rang. 

 Fig. 17 is a smaller shell copied from Sowerby. My description is 

 from Rang. 



The dentition has been worked out by Bergh from specimens col- 

 lected by Riise. His figures are here reproduced. PI. 65, figs. 10, 11, 

 shell ; pi. 67, fig. 25, median and first lateral teeth ; fig. 21, laterals 

 from inner fifth of a row, from the side ; fig. 24, laterals of the fol- 

 lowing fifth, from above ; fig. 22, laterals from the third fifth, viewed 

 from the side ; fig. 23, the outermost laterals. 



D. SWIFTII n. sp.. PI. 67, figs. 19, 20. 



Soft parts unknown. Shell trapezoidal with projecting beak, well 

 curved, moderately solid, but not much calloused within ; white 

 with thin yellowish cuticle. Sinus long, concave; left margin 

 straight ; basal or anterior margin truncated at a right angle with the 

 left margin, and distinctly emarginate; right margin below the sinus 

 parallel with the left, but gently convex. Beak obtuse, with a flat, 

 callous extension, roughened and thickened on the ventral side. 

 Length 11, breadth 5? mill. 



West Indies (R. Swift). 



The shell of this species somewhat resembles that of D. fusca, as 

 figured by Pease, but the sinus is more equally concave, and the 

 narrow extension of the beak longer. 



