PTYCHAL/EA. 273 



peristoine is continuous, the dorsal impressions are not deep, 

 and it coidd hardly have been described as flexuose forte 

 cantata. 



It was these specimens from Pease which the senior author 

 referred to as Nesopu-pa (Lyropupa) coxtata, in Proc. A. N. S. 

 Phila., 1900, p. 432. Other authors who have mentioned the 

 species knew it only by Pease's description. 



At present therefore V. costata appears to be a lost species 

 of uncertain genus ; unless the type comes to light it must be 

 dropped as unrecognizable. 



Genus PTYCHAL^EA Boettger. 



This volume, pp. 157, 220. 



This group was proposed for a Lower Miocene species of 

 Europe ; a recent species of the Bonin Islands appears to agree, 

 but the writer has not seen the fossil genotype. 



They differ from Nesopupa chiefly by having a strong crest 

 behind the lip, as in many Vertigos. This is not usually a 

 character of much importance, but it is absent in the long 

 series of species referred to Ncsopupa. Boettger himself made 

 a distinction between Ptychahea and Pti/cJiocfiilus (= - Ncso- 

 pupa), both of whicli he recognized in the European Tertiary. 



We now consider Ptychalaea incorrectly placed in Vertigo. 

 We are strongly disposed to subordinate Nesopupa, Coxtigo 

 and Pro-nesopupa to Ptychalaea as subgenera ; yet specimens of 

 the fossil type of the latter are not at hand, and species inter- 

 mediate between Ptychalaea and Nesopupa have not been 

 found. At present we admit several genera, Nesopupa, 

 Pronesopupa and Costiyo, among the Polynesian and Oriental 

 Vertigininae as a temporary expedient, rather than as an ex- 

 pression of definite conviction. It is quite probable that a 

 study of the dentition would yield characters of value in 

 tins inquiry. 



1. PTYCHALAEA DEDECORA (Pils.). P. l.~>,s. 



The fossil species P. flexide-n-s Reuss, and possibly ca-pellinii 

 Sacco belong here. The other species enumerated under 

 Pti/chakca on p. 220 belong to Nesopupa. 



