56 
plain. Laterally and posteriorly the mantle is produced to form a wing-like extension, 
commeneing just dorsal to the respiratory orifice and passing around the posterior border 
it terminates on the left side near the anterior edge of the mantle. Posteriorly the body 
is much compressed, dorsally forming a well pronounced keel. Caudal mueous pore slit- 
like. Peripodial groove distinet. Foot-sole brownish-yellow. 
Lensth (in alcohol) 19 mm. 
Shell a thin membranaceous covering of the visceral mass, with a few isolated 
ealcareous particles beneath. Major diameter about 7,5 mm, minor diameter about 5 mm. 
Hab. Island of Busuanga. Type in my collection. 
On dissection it was found that the generative organs were only partially developed. 
The penis was not unlike the condition which obtains in the young of certain species of 
Parmarion. Both P. quadrasi and P. carinata I regard as young examples of 
two distinet species. 
P. CARINATA, Miurorr. 
Tennentia carinata, MLLDFF., 1894, Nachr. d. Deutsch. Malak. Gesellsch. p. 85. 
Animal much lichter than P. quadrası. Mantle convex completely covering 
the shell, not so coarsely granulated anteriorly as in the preceeding species, and not 
quite as smooth posteriorly. Lateral and posterior extensions slightly smaller. The body 
is compressed posteriorly and produced dorsally into a well defined keel. "The overhaneing 
lobe above the caudal mucous pore does not extend beyond the length of the foot-sole. 
Length (in alcohol) 16 mm. 
Shell better developed than in P. quadrasi. The calcareous granules form a 
compact oval-shaped mass, covered by a thin membranaceous covering which is almost 
transparent. Major diameter about 6,5 mm, minor diameter about 3 mm. 
Hab. — Island of Sibuyan (Ü. ROEBELEN); type in my collection. 
P. MÖLLENDORFFI, n. sp. 
Animal yellowish with short bluish lines at each side immediately behind the 
head. Visceral mass large. Mantle convex, completely covering the shell, bluish-green 
anteriorly, dark blue posteriorly, laterally marked by a well pronounced keel, commen- 
eing on the riecht side just in front of, and above, the respiratory orifice, it passes back- 
wards and curves around the postero-dorsal portion of the mantle, the left half passing 
forwards to almost the extreme anterior and border of the thin mantle edge. Caudal 
mucous pore slit-like, body laterally eompressed, keel prominent. Tail truncated. Gene- 
rative orifice behind the richt tentacle. Peripodial groove distinct. Foot-sole yellowish-brown. 
Length (in alcohol) 24 mm. 
