164 TITISCANIA. 



P. LATICOSTATA Blainv., L. c., p. 111. Probably this is P. negleda 



Gray. 

 P. NIGROALBA Blainv., L. c., p. 111. Unidentified. Cape Good 



Hope. 

 P. PERONII Blainv., L. ., p. 111. Unidentified. Port of King 



George, Australia. 



P. MADAGASCARENSIS Blainv., L. c., p. .112. Unidentified. 

 P. VIOLACEA Blainv., L. c., p. 112. Perhaps P. vulgata. 

 P. ATROMARGINATA Blainv., L. c., p. 113.=P. gmnularis. 

 P. SUBGRANULARIS Blainv., L. c., p. 113.=P. lusitanica. 

 P. ZEBRA Blainv., L. c., p. 115. Unidentified. 

 P. UNGULIFORMIS Blainv., L. c., p. 115. Unidentified. 



Family TITISCANIID^E. 



Animal limaciform, naked, without a shell ; radula rhipidoglosate, 

 neritoid, but lacking median teeth like the Neritopsidce. 



This shell-less, limaciform type belongs, as its internal anatomy 

 and the armature of the radula show, to the group of the Neritacea; 

 and the lack of median teeth places it evidently in the Neritopsoid 

 division of that group. 



Genus TITISCANIA Bergh, 1890. 



Titiscania BERGH, Morphol. Jahrbuch, xvi, (1), p. 3. Type, T. 

 limacina. 



T. LIMACINA Bergh. Plate 41 ; pi. 39, figs. 28, 29. 



Form quite limax-l'iks, long-oval, convex above, flat beneath, 

 rounded in front and behind. The color above is clear yellowish, 

 whiter in the middle, where the violet-gray entrails show through, 

 and with a few whitish transverse bands. The back is quite even, 

 only with a few white salient points; anteriorly above is the trans- 

 verse branchial slit, the end of the gill projecting out of the slit in 

 several individuals. The gill has 35 to 40 laminae. In front of the 

 gill-slit is the flat and rather wide head with rather long, pointed 

 tentacles, having the black, nearly sessile eyes at their outer bases. 

 In the male there is behind the right eye a little whitish hump or 

 pit (opening) for the end of the seminal duct. The entire length 



is 10? mill. 



Camiffuin, Philippines; Mauritius. 



