4 HELIX-PAPUINA. 



The species are illustrated on plates 1 to 17. 



No exact diagnosis can be framed for a group in which such 

 diverse forms occur as in Papuina. It is still, however, an easy 

 matter to recognize a species as belonging here; for with all its 

 variety, the group is a very natural one, well differentiated from 

 other branches of the Helix stock. The central point for the sub- 

 genus, geographically, is New Guinea ; the species extending eastward 

 to the Louisiade, Admiralty and Solomon Islands, with a few in the 

 New Hebrides, and northwestward into the Moluccas. The distribu- 

 tion is, therefore, practically the same as that of the subgenus 

 Chloritis (-}- Planispira, etc.) 



In a previous volume the writer has separated the South American 

 group Oxychona from Papuina. It remains to sunder the species of 

 southeastern Asia and the zoologically dependent islands, which will 

 be discussed after the true Popiu?ia-species. The latter form a 

 moderately homogeneous group, in which it is practically impossible 

 to establish " sections " to correspond to the various names given in 

 the above synonymy. It seems to me a better plan to form the 

 species into a number of groups, each typified by its more prominent 

 specific type. These groups are of somewhat unequal value, and 

 bear various degrees of affinity to each other ; but they undoubtedly 

 form a basis for a natural system. It is likely that anatomical char- 

 acters will afford a good clue to the minor groups. 



I. True PAPUINA ; including species of the Moluccas, New Guinea, 

 Australia, Admiralty, Solomon, Louisiade Is., etc. 



(1.) GROUP OF H. BOIVINI. 



Imperforate, turbinate, the periphery rounded or bluntly angled ; 

 upper lip not expanded or but narrowly expanded ; banded. Sur- 

 face smooth, lightly obliquely striatulate, sometimes having faint spiral 

 lines, but no forward-descending wrinkles. 



H. CONGRUA Pfeiffer. PI. 9, fig. 72. 



Imperforate, trochiform, rather solid, striatulate, flesh-colored, 

 variously painted with brown bands ; spire subcon cave-conic, apex 

 a little obtuse. Whorls 6, a little convex, the last irregularly 

 inflated, slightly descending, distinctly rib-striated ; base nearly flat, 

 more shining. Aperture oblique, subtetragonal-oval ; peristome 

 blackish-chestnut, expanded, encircled by a streak outside, margins 



