OPEAS, COMORO IS., ETC. 153 



whorls, separated by a very distinct suture, is elongated in 

 the form of an awl. The stria with which it is engraved 

 from about the fourth whorl, are very irregular. The epi- 

 dermis is of a uniform brown color without gloss. The long 

 and narrow aperture is slightly effuse at the base. The colu- 

 mella is not truncated, but it is a little twisted spirally." 

 (Morelet). 



29. 0. AVENACEUM (Morelet). PI. 16, figs. 86, 87. 



"Shell imperf orate, oblong, thin, somewhat glossy, smooth, 

 brownish-waxen; whorls 7 a little convex, the last equal to 

 three-sevenths the entire length of the shell. Columella 

 straight, obliquely truncate, not reaching the base. Aperture 

 semi-oval, margins simple unexpanded. Length 7 diam. 2^2 

 mm." (Morelet). 



Comoro Islands: Mayotte (Marie). 



Stenogyra avenacea MORELET Jour, de Conch, xxix, July, 

 1881, p. 219, pi. 9, f. 3. 



" It is distinguished from S. johannina, which is much more 

 shining, by being imperforate ; from gracilis and clavulina by 

 the truncate columella; from mauritiana (a doubtful form) 

 by the two preceding characters and its absolutely smooth 

 surface. The other species of the same group are much 

 larger. The columella, in this shell, is obliquely truncate 

 before reaching the base ; the aperture forming a round shal- 

 low sinus below the truncation." (Morelet). 



The specimen drawn in fig. 86 is from E. Marie. I am 

 entirely inclined to place this shell in Opeas. The oblique 

 truncation of the columella is not greater than in 0. layardi 

 and some other species. The very fine growth-stria are al- 

 most straight, not distinctly arcuate as in Opeas generally. 



30. 0. JOHANNINUM (Morelet) . PI. 23, figs. 16, 20. 



"Shell subimperf orate, turrited, rather solid, arcuately 

 hair-striate, shining, diaphanous, white or pale yellow, in 

 specimens a long time dead, waxen ; spire elongate, conic, some- 

 what acute, whorls iy 2 , slightly convex, the last equal to two- 

 fifths the length of the shell ; columella almost vertical, gradu- 



