PLEUROBRANCHUS, HALIOTINELLA. 209 
behind like the foot, borders of mantle and foot not projecting be- 
yond each other. Penis not visible externally. Small black eyes: 
at bases of the tentacles ; tentacles blunt in front. Gill with 23-25 
branches. Length one inch. 
Shell lying in about the middle of the back under the mantle, 
but a little toward the right over the gill ; very small but relatively 
- thick, caleareous, narrow and white behind, wider and _ reddish- 
brown in front, resembling the shell of Pinna in respect to contour. 
Consists of united layers. Length 2 lines. (R. & L.). 
Gulf of Suez, on the shore; collected in February. 
Pleurobranchus citrinus R. & L., Atlas zu der Reise im Nérd- 
lichen Afrika von Eduard Rtippell, Neue Wirbellose Thiere des 
Rothen Meeres, p. 20, pl. 5, f. 1 (1828).— EHRENBERG, Symb. Phys. 
Decas 1, No. 1.—IsseL, Mal. Mar Rosso, p. 162.—? Sowersy in 
Reeve, Conch. Icon., xvii, pl. 1, f. 7—Probably not P. citrinus ? 
Kevaart, Ann. Mag. Nat. Hist. (3), ili, p. 495. 
Sowerby gives a figure of the shell, said to be copied ; but he mis- 
quotes Ruppell’s page and figure, and there is no illustration of the 
shell in Rtippell’s work. 
P. zEYLANICYS Kelaart. Unjigured. 
Pale yellow, splashed with darker yellow and brown, and minutely: 
spotted with rusty brown. About 2 inches long. (Kel.). 
Back Bay, Ceylon (Kel.)- 
Pleurobranchus zeylanicus Kex., Ann. Mag. Nat. Hist. (38), iti, p. 
495 (1859); Journ. Ceylon Branch Roy. Asiat. Soe., iii, pt. 1, p. 
111 (1883). 
?Genus HALIOTINELLA Souverbie, 1875. 
Shell umbilicated, auriform, with an epidermis, thin, much de- 
pressed ; spire posterior, very short, many whorled; whorls few, the 
last very ample, forming the greater part of the shell; aperture 
very large, the margins not joined, left margin inflexed below, re- 
flexed at the columellar insertion ; soft parts unknown. (Sowv.). 
The genus was provisionally placed by Souverbie in the vicinity 
of Sigaretus. Morch declares it to be based on a Pleurobranchus. 
shell; and Fisher locates it with doubt in Plewrobranchide. JI am 
disposed to agree with the view expressed by Mérch. 
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