THREE SPECIES OF PLEUROTOMARIA. 
This genus is mostly found in the seas about the West Indies, Japan and the Molucca Is. It must have 
existed in great numbers in prehistoric periods, for their fossils are found abandantly in all parts of the world, 
and the species of fossils collected and determined up to date are over 1,100. It had been believed an extinct 
genus up to 1856 when a shell of a recent species was found. In 1871, a living species was found by A. Agassiz. 
The number of species well known to the world was five until Dr. Pilsbry found another new species among 
the specimens from Tosa, Japan, which our president had sent him for identification, and named it P. /drase? in 
honor of its discoverer. So there are now six species in all. The characteristic of this shell is a deep slit at 
the upper edge of the lip. 
The specimen on the left : — P. salmiana Rolle. 
The middle : — P. beyrichi Hilgendorf. 
The right : — P. hirasei Pils, 
k# R= i 
FSO) PB (BRA -AEAAM) LG. ARM ry ABS EL A ARB} YI 
MRO L LO sae 5 ILA. RPA PAE CE OR (LP. guoyana Crosse and Fischer) #8,+ 6 hv. 
FARE. ry XK (A. Agassiz) kh CAN O/EA ABH LILY. HR HHDSY LseErAZzTy) Th 
ELSE OEY LAKH O—-FI EF RAE HAC ONTRALRUCHNARARTACENY. HRCA WAd 
D7eK MO HBS FT. . 
WMoOotCH azyeaArxe rz ACHE) CZ. salmiana Rolle.) 
ip he Fete CP. beyrichi Hilgendorf,) 
A Me SHA Pez AMB) CP. Aivasei Pilsbry.) 
