122 DOLABRIFERA. 



D. FUSCA Pease. PI. 34, figs. 1, 2, 3, 4, 5. 



Shell elongate, triangular, right side straight, left side slightly 

 curved towards the apex, surface decussated with strife, lower half 

 grooved longitudinally in the middle; base roundly truncate; apex 

 callous ; whole shell slightly bent. 



The shells of all the species I have seen, inhabiting Polynesia, are 

 callous at the apex to secure the ligament which holds the shell. 

 They also differ from those heretofore described, in being of a more 

 triangular shape. The one herewith figured may be taken as the 

 type of them all. 



Animal oblong, pyriform, widest posteriorly, and gradually taper- 

 ing in front. Surface smooth, margins thin and ruffled, rounded 

 behind. Eyes immersed, a little anterior of the dorsal tentacles ; 

 tentacles openly convolute, dilated at their extremities and crenate. 

 Color above uniform brown, right lobe, which covers the gills, mar- 

 gined with white ; beneath pale bluish centrally, passing into pale 

 brown, and closely freckled with darker brown and white. (Pse.). 



Tahiti f 



D.fusca PSE., Amer. Journ. Conch., iv, p. 76, 160, pi. 8, f. 4 ; pi. 

 12, f. 27. (Oct. 1,1868.) 



Station under stones, in the upper region of the laminarian zone. 

 The peculiarity of this species is the character of its margin adapted 

 for swimming. (Pse.). 



D. PACIFICA Pease. PL 34, fig. 18. 



Soft parts unknown. Shell thin, straight, oblong ; beak wide,, 

 apex incurved, slightly thickened; basal margin elongated, rather 

 straight; terminal margin roundly angular; outer margin subsinu- 

 ous in the middle. (Soivb.'). 



Islands in the Pacific (Sowb.). 



D. pacifica (Pease) SOWB., Conch. Icon., xvi, October, 1868, f. 3. 



D. OAHOUENSIS Souleyet. PI. 22, figs. 6, 7, 8, 9. 



Length 7-8 cm. Body much swollen, elongated and contracted 

 in front, visibly prolonged behind, but not terminating in a point- 

 Surface smooth. Green, tinted with rose in some places, and marked 

 throughout with small spots of very deep green, almost blackish. 

 Pleuropodial lobes close on the back, leaving a very narrow fissure 

 between them. 



