148 GONOSTOMA. 



Genus HELIX Linne. 

 Subgenus GONOSTOMA (Vol. Ill, p. 114.) 

 H. ANNAI Paladilhe. PL 43, figs. 47, 48, 49. 



Placed by Tryon under H. lenticula as a variety in Vol. III,, 

 p. 119. Specimens sent by Mr. John Ponsonby show that it is a 

 well-defined species. The shell is umbilicated, width of umbilicus 

 contained about 4 times in greatest diameter of the shell (in len~ 

 ticula nearly 6 times) ; form depressed, slightly convex above, roundly 

 angled at the periphery, which is near the top of the whorl, the base 

 very convex. Surface very finely striated (not regularly and 

 coarsely costulate as on the spire of lenticula). Whorls 41, convex, 

 slowly increasing. Aperture oblique, narrow ; lip thin, not in the 

 least thickened or expanded. Alt. 3, diam. 62 mill. 



Tangier. 



Helix annai PAL., Kev. et Mag. Zool. 1875, p. 82, t. 6, f. 13-18. 



Mr. Ponsonby writes: " I have collected many, both at Tangier 

 and near Gibraltar. They never seem to be larger or fuller grown, 

 nor to have any tendency toward H. lenticula." To which it may 

 be added that the young are perfectly distinct from young lenticula. 



H. COLUMNS Ponsonby. PI. 34, figs. 82, 83, 84. 



Shell broadly and openly umbilicated, depressed, nearly circular 

 in circumference, lenticular, surrounded by an acute carina ; spire 

 depressed, conic, narrow whorled, apex minute, slightly flattened ; 

 rather solid, little translucent, unicolored corneous-brown, paler 

 beneath. Whorls 8, very slowly increasing ; suture impressed, at 

 first linear, then subcrenate ; earlier whorl smooth, convex ; follow- 

 ing a trifle convex, very distinctly sculptured with distant, arcuate 

 riblets. Last whorl scarcely dilated, the basal convex, begirt with 

 an acute serrated carina a little above the middle, costellate above, 

 smoother and striated below, slightly descending in front. Aperture 

 oblique, produced above, receding below, irregularly lunate-ovate, 

 angled outwardly ; peristome thin, lipped with whitish, the margins 

 distant, upper margin straight, acute, lower margin reflexed, thick- 

 ened, columellar margin a little dilated at the insertion. (Kob.~) 



Alt. 10, greater diam. 20, lesser 18 mill. 



Top of Apes'- Aft., opposite Gibraltar. 



Helix ( Gonostoma) columnce Pons. mss., KOBELT, Nachr. D. M. 

 Ges. xxi, 1889, p. 140; Rossm. Icon. N. F., p. 79, t. Ill, f. 662. 



