82 PROCEEDINGS OF THE ACADEMY OF [1889. 



cording to Mr. Smith, the species is abundant at the locality given 

 above, although not found in the surrounding country. Like the 

 other species of Holospira it lives upon rocks. Movement upon 

 a horizontal surface is evidently a difficult feat, the heavy shell 

 rolling from side to side in a most embarrassing way ; but on the 

 perpendicular sides of a glass jar, Elizabeth's Holospira is quite at 

 home, moving slowly but easily in any direction, the graceful shell 

 always hanging vertically. 



Helix (Microphysa) hypolepta Shuttleworth. PI. Ill, figs. 6, 7, 8. 



Of this minute form no diagnosis or figures have been published, 

 although the name has been upon the lists for many years. The 

 shell was apparently unknown to Pfeiffer except by the remarks of 

 Shuttleworth, who says under his diagnosis of H. minuscula Binn. : 

 " Altera species proxima, sed testa aperte umbilicate, et anfr. 

 ultimo basi devio distincta, in insula Bermuda occurrit, cujus speci- 

 mina pluriina ab am. Bland accepti, atque H. hypolepta nominavi." 



The shell is minute, discoidal, whitish, subtranslucent and shining, 

 with wrinkles of increment above, nearly smooth beneath. The 

 four whorls are very convex, quite gradually widening, the last one 

 with the periphery above its middle, the lower lateral surfaces slop- 

 ing somewhat as in H. vortex Pfr. The aperture is small, not very 

 oblique, oval. The lip is acute, upper and basal margins quite 

 arcuate, the baso-columellar margin slightly expanded. The um- 

 bilicus is broad, more than one-third the diameter of the shell. 



Alt. 1, diam. 2| mill. 



It is evidently allied to H. (Microphysa) vortex Pfr., but is much 

 smaller, flatter, with broader umbilicus. I need not compare 

 Zonites minusculus with this shell ; a glance at the figures will 

 show at once the difference. 



Helix hypolepta. Shuttleworth, Diagnosen neuer Mollusken, no. 

 6, from the Bern. Mittheil., March, 1854, p. 129. 



The group Microphysa, in which I have placed this shell has been 

 a stumbling block to most of the authors who have recognized it. 

 It consists of small, umbilicated, thin, hyaline shells, with sharp lip 

 to the lunar-oval aperture, convex whorls and impressed sutures. 

 There is little in all this to separate it from certain forms of Zonites 

 (Z. minusculus, for example). But the Zonites have narrow aculeate 

 marginal teeth to the radula, while these shells, typified by H. 

 boothiana Pfr., have the dentition of Patula. The marginal teeth 

 are low, wide, with several denticles. 



