HELIX. 141 



In addition to Bourguignat's figures of this form, I give those of 

 Kobelt, (PI. 61 figs.13-15.) According to the latter author, the species 

 is not found upon the island of Rachgoun, but at Nemours. There 

 is also some difference between the two authors as to the concholog- 

 ical characters of the species, Kobelt's form being less striate above, 

 and measuring 26 mill, in diam., 17 in alt. 



H. PSEUDOEMBIA Debeaux. PI. 42, figs. 58, 59. 



Subglobose, imperforate, solid, chalky, white, with irregular in- 

 cremental striae and short transverse impressed lines ; whorls 5 y 

 slightly convex ; suture moderately impressed ; last whorl inflated r 

 depressed around the umbilical area, strongly deflexed in front ; 

 aperture oblique, lunate, bright chestnut colored inside and on col- 

 timella ; peristome acute, the margins converging, joined by a light 

 callus ; peristome widely reflexed, albolabiate, obsoletely dentately 

 thickened inside the outer lip ; columella subexcavated, with a dis- 

 tinct white, truncate, dentiform fold. 



Diam. 32, alt. 21 mill. 



Leila Mar ma, Morocco, between Nemours and Tlemcen. 



Allied, according to Kobelt, to H. zaffarina. Its relation to H. 

 embia seems quite as close, and with that species it forms the transi- 

 tion to " die Gruppe der Doppel-Zahner," as Kobelt calls the follow- 

 ing species. Most of these are probably merely local races ; for like 

 many of the northern African shells the characters upon which the 

 species are founded, such as texture, development of mouth parts, 

 etc., are endlessly variable ; every locality, with its slightly differing 

 soil and climate producing a new and correspondingly differing race 

 of mollusk. 



H. BURINI Bourguignat. PL 42, figs. 60-62. 



Imperforate, convexo-globose, shining, elegantly striate, white, 

 with four brown bands; spire conoid, apex obtuse; whorls 5-6, 

 slightly convex, regularly and slowly increasing, the last rounded, 

 anteriorly descending; aperture very oblique, lunate-oblong, white 

 within ; peristome expanded, labiate, with a long basal tooth and a 

 lamelliform denticle within the outer lip. Diam. 27 mill. 



Southern Oran, Algiers- 



Teeth not much more developed than in If. pseudoembia. 



H. TIGRI Gervais. PL 42, figs. 63-65. 



Imperforate, orbicularly depressed, solid, shining; convex below; 

 whorls 5, slightly convex, the last profoundly deflexed anteriorly, 



