202 Doll A New Proserpinoid Land Shell from Brazil. 



full diagnosis of Cyane, that the chief character upon which 

 Adams based his genus may have been of a like nature, in which 

 case it could hardly be accounted of generic value. 



From Cyane, however, the present species differs in preserv 

 ing a parietal lamella; and, as Bland, Pfeiffer and others have 

 considered differences of the arrangement and number of the 

 lamella? of the aperture as sufficient characters for subdivisions 

 of the genus, the Brazilian shell might be regarded as constitut 

 ing the type of a section or subdivision with those characters, 

 which might be called Staff ola. 



Proserpina (Staff ola) derby i sp. nov. 



Shell small, depressed, pale yellowish, when fresh probably polished, 

 with an axial sculpture of fine, non-punctate, sharply incised striae nearly 

 parallel to the incremental lines, but visible only under considerable mag 

 nification; spire depressed, domelike, the sutures obscure, the protoconch 

 large, followed by five whorls; base flattish, imperforate, not excavated in 

 the center; aperture semilunar, outer lip thin, sharp, advancing slightly 

 from the suture and slightly excavated just before it joins the pillar ; parietal 

 wall with a single lamella about one-third of the way from the pillar to 

 the suture; periphery of the shell inflatedly rounded ; the armature of the 

 pillar has been already described ; height of shell, 2.5 ; max. diam., 5.0 ; 

 min. diam., 4.0 mm. 



The shell is in such a condition that it might be either a Pleistocene fos 

 sil or a " dead " shell washed from a higher level and stranded by falling 

 water in the creek. 



The Proserpinidre have hitherto been known only from the Antilles, 

 Mexico, middle America and the shores adjacent to the Caribbean, except 

 in the case of Cyane blandiana Adams, which was described from Eastern 

 Peru. The presence of a species in the State of Bahia is therefore a very 

 interesting addition to the knowledge of the geographical distribution of 

 members of this group. Even if fossil, it carries the range 1,000 miles to 

 the south and east, and adds weight to the connection which has been 

 already insisted on between the Antillean fauna and that of the Eastern 

 portion of South America south of the Amazonas. 



