532 



PROCEEDINGS OF THE ACADEMY OF 



[Sept., 



Geomelania (Scalatella) microglypta n. sp. Fig. 13. 



The shell is minutely rimate, slender, columnar, 

 tapering very slowly to the obtuse (truncated) 

 summit, grayish-white. 6^ whorls remaining are 

 very convex, the suture deeply impressed. Sculp- 

 ture of longitudinal ribs somewhat wider than the 

 intervals, and about .055 mm. from crest to crest, 

 on the last two whorls; over the ribs and intervals 

 run many fine spiral threads, of which there are 

 about 36 on the penultimate whorl. The aperture 

 is ovate, outer lip obtuse, expanded ; in profile straight 

 or slightly concave above the periphery, regularly 

 arching forward at the lower outer portion. Length 

 4.1, diam. 1.1, length of aperture 1 mm. 



Near Mandeville. Types No. 101,345, A. N. S. P., 

 collected by A. P. and S. Brown, 1910. 



In figure and size this species hardly differs from 

 G. pygmaea ('. B. Ad., but the sculpture is very much 

 finer and closer. 



Fig. 13. 



Rhytidopoma fraterminor " Bp. Big. 14. 



The shell is perforate, turrite, rather slender, thin, variable in color: 

 dark reddish-brown, the stri:r lighter, or pale yellow 

 with vertical series of brown spots formed by the 

 interruption of spiral bands, of which there are six 

 on the last whorl, the next to the lowest one nearly 

 continuous; or it may be uniform pale yellowish. 

 In individuals retaining the spire the latter tapers 

 regularly to the obtuse apex; but the early whorls 

 are usually lost, leaving 5 to 5^ in adult shells. 

 Whorls 1h, strongly convex, the last fourth of the 

 last whorl descends, running free from the preceding 

 whorl, separated from it at the aperture by a distance 

 about equal to the width of the outer lip. The 

 embryonic shell consists of 2 whorls, the first H 

 smooth, the next half whorl minutely striate. After that sharp 

 strongly raised, narrow striae appear, arranged in groups of 3 or 4 on 

 the third whorl, mostly by pairs on the next two whorls; after which 

 the striae are in groups of 4 or 5, the first one largest, the rest gradually 

 diminishing. The groups are separated by plain spaces. On the last 

 3 or 4 whorls two or three larger striae of each group become higher 

 and lamellar near the suture above, where they project strongly. 



Fig. 14. 



