192 HELIX-CAM^ENA. 



H. BORDAENSIS Angas. Vol. IV, pi. 36, figs. 41, 42, 43. 



Shell widely and deeply umbilicated, lenticular, moderately thin, 

 very strongly and irregularly obliquely flexuously corrugated, the 

 corrugations becoming larger and more elevated toward the middle 

 of the whorls ; cretaceous, white ; spire depressed, apex obtuse ; 

 sutures very strongly impressed and carinated. Whorls 5, nearly 

 flat, the last depressed and strongly keeled above the periphery, not 

 descending in front, slightly keeled around the umbilicus. Aperture 

 oblique, semilunar ; outer lip simple ; columella very slightly 

 expanded ; margin united by a thin callus. (AngasS) 



Alt. 6J, greater diam. 16, lesser 14 mill. 



Cape Borda, Kangaroo Island, S. Australia. 



H. bordaensis ANGAS, P. Z. S. 1880, p. 419, t. 40, f. 3. 



This remarkable shell exhibits a somewhat similar sculpture to 

 H. silveri Ang., and H. kooringensis Ang., but it differs from both 

 these species in having the raised corrugations more numerous and 

 elevated, displaying at the sutures and on the keel an elegant frilled 

 appearance. It is also smaller, flatter, has a wider perspective 

 umbilicus, and the corrugated ridges show here and there a tendency 

 to bifurcate. (Angas.} 



Subgenus CAM^ENA Albers, 1850. 



Helices of rather large size, capacious, subglobose or depressed, 

 usually carinated, the surface generally malleated or obliquely 

 wrinkled ; lip expanded or reflexed ; umbilicus narrow or closed. 

 Embryonic shell (and consequently the egg) comparatively large, 

 but smaller than in Acavus. 



The characters of this group seem to place it between MACEOON 

 (Helicophanta -f- Stylodonta -\- Panda -f- Acavus) and HADRA. 



Broader knowledge of the Oriental Helices causes me to modify 

 the arrangement set forth on page 89 of this work. I now relegate 

 Thersites to Hadra as a section having but slight individuality; 

 Camwna had better for the present be considered a subgenus, rank- 

 ing with the other groups so denominated in this work. The determi- 

 nation of its final rank and position awaits a knowledge of the 

 anatomy, still lacking. 



It must constantly be borne in mind that the Camcena of which I 

 write is a completely different group from the heterogeneous assem- 

 blages of species under that name in the works of Pfeiffer and 

 authors generally. The Australian group of Helices, Hadra, and 

 the Japanese, Euhadra, seem to me to have nothing to do with 

 Camvena. 



