HELIX-HADRA. 149 



slightly obtuse ; whorls nearly 5, convex, last inflated, scarcely de- 

 scending in front, somewhat compressed about the moderate, per- 

 vious umbilicus ; aperture diagonal, lunately rounded, pearly with- 

 in ; peristome brownish, fleshy, everywhere shortly expanded, mar- 

 gins somewhat converging, columellar margin dilated above, re- 

 flected in a vaulted manner. (Pff.) 



Alt. 9, greater diam. 15, lesser 12 mill. 



Admiralty Is. ; var. 0. in North Australia. 



H. murina PFR. P. Z. S. 1856, p. 384 ; Monogr. iv, p. 268. 



Var. 0. Paler, brownish-horn colored, peristome white. 



A species of doubtful position, not yet identified by Australian 

 naturalists. 



H. PLICULOSA Pfr. (MANUAL iii, p. 216), H. VICTORIA Cox, 

 and some other species may prove to belong in this group. 



Subsection SPHJEROSPIRA, Morch, 1867. 



Sphcerospira MORCH, Journ. de Conchyl. 1867, p. 256, for H.fra- 

 seri, lessoni, appendieulata. 



The Australian Sphcerospira form a natural group of very closely 

 .allied species. It seems obvious to me that a considerable number 

 of the described forms say 25 per centum are merely geographic 

 races or color-varieties, not really entitled to specific rank. (Com- 

 pare croftoni with coxi; gratiosa with blomfieldi, etc., etc.). I have 

 preferred to indicate, rather than actually make, many of the more 

 apparent reductions, as my material is not extensive enough to show 

 the actual coalescence of many forms which I have reason to believe 

 belong together. This work of revision should be done by some 

 Australian student. The genitalia as well as the shells must be ex- 

 amined, as in many groups of Helix they offer excellent specific 

 characters. 



The primitive coloration, toward which all the species tend, is as 

 follows: the suture is narrowly edged with white, followed by a 

 dark brown band ; another dark band encircles the whorl above 

 the periphery, and the inside of the umbilicus is dark. This pattern 

 is chiefly modified by the addition of numerous narrow lines, or by 

 their coalescence, resulting in either a multilineate or a uniformly 

 dark shell. 



Fuller knowledge of the forms of Hadra has convinced me that 

 the division of that section into three subsections (see p. 94) is at- 

 tended with difficulties. Badistes, Sphcerospira and Hadra proper, 



