PSEUDOPEAS. 117 



ornamented with, a fine and superficial costulation inter- 

 mingled with simple striae ; but it has a whorl and a half less, 

 the last, by its development, approaches more to a bulimoid 

 form. These differences, which seem sufficient to justify a 

 separation, are accompanied by other modifications of detail ; 

 the columella is less dilated, the aperture is larger and the 

 points -of insertion of the peris-tome are much more remote. 

 This last character is very apparent." (Morelet). 



A specimen not quite full grown, of 5 whorls, is figured. 

 The apical whorl is very finely and densely engraved spirally, 

 though this sculpture is visible only under the compound 

 microscope. 



4. P. EGENS (d'Ailly). 



Shell minutely perforated, turrited, densely arcuately pli- 

 cate-striate, pale corneous, thin, diaphanous, with a waxen 

 luster. Spire turrite, the apex rather obtuse. Whorls 6, the 

 embryonic ones a little convex, seen under a lens to be very 

 minutely and densely striate spirally; the following whorls 

 flattened, more or less terraced, regularly increasing, separ- 

 ated by an impressed suture, under the lens seen to be deli- 

 cately crenulate and indistinctly margined; last whorl two- 

 fifths the length, angular or terraced at the suture and com- 

 pressed around the perforation. Aperture oblong, vertical, 

 peristome simple, the margins joined by a very delicate cal- 

 lus, the right margin arching forward, unexpanded, colu- 

 mellar margin with a long reflection; columella subvertical, 

 generally bending a little towards the left. Length 5 to 6, 

 diarn. 1.5 to 2 mm. (d'Ailly). 



Kamerun: Kitta (Sjostedt). 



Opeas egens d'AiLLY, Moll. terr. et d'eau douce de Kam- 

 eroun, in Bihang till K. Sv. Vet.-Akad. Handl., xxii, p. 

 113 (1896). 



The spiral sculpture of the protoconch ''is of extreme fine- 

 ness, and may be seen distinctly only under a strong lens in 

 a favorable light. Almost all of our examples contain per- 

 fectly spherical eggs arranged in a single series in the oviduct, 

 visible by transparence through the shell." 



