338 SMITH : TWO SPECIES OF MADAGASCAN HELICES. 



in associating with their names their ovm respective discoveries. 

 The H. Covani is especially interesting as very closely representing 

 in the eastern hemisphere a form occurring in Chilli. 



In addition to this Helix the British Museum obtained from 

 Mr. Cowan a fine example of the species originally described by 

 Shuttleworth under the name of Spiraxis exiinia, and more recently 

 by Angasin the ' Proceedings of the Zoological Society for 1877,' 

 as Bidimiis balstoiii. In the second part of Shuttleworth's 'Notitise 

 Malacologicse' (p. 13), it is placed in the genus Colmima, which 

 location is sanctioned by Pfeiffer in vol. viii. (p. 252) of his 'mono- 

 graphia Heliceorum.' It does not however appear to me to be 

 conveniently placed, and its character in my judgment is rather 

 that of Stenogyra. 



Helix (Macrocyclis) Covani. 

 Shell broadly and openly umbilicated, moderately thick, 

 orbicularly depressed, lightish-brown becoming more olivaceous 

 upon the spire, decussately sculptured with fine spiral striae and 

 oblique lines of growth producing a subgranulated surface. Spire 

 depressed, with slightly convex outlines and a somewhat raised 

 apex. Whorls 5-5 J in., rather convex, enlarging moderately slowly 

 and separated by an impressed suture. Last volution large, 

 rounded at the periphery, a little descending and compressed 

 anterior!}^, more feebly sculptured beneath, except within the 

 umbilicus, than above, and exhibiting no trace of an angulation 

 around the umbilicus. The latter is open and perspective to the 

 apex. Aperture oblique, white. Peristome subsimple; its upper 

 margin prominent in the middle, thin, apparently scarcely expanded, 

 collumellar edge slightly thickened, expanded and reflexed. 

 Greatest diameter 36 mill., smallest 30, altitude (resting upon its 

 base) 16 mill. 



This species is very like the Chilian H. laxaia. The general 

 form is the same, and the open character of the umbilicus is 

 similar and the absence of any angulation in that region upon the 



J.C., ii., Nov., 1879 



