235 TRANSACTIONS OF THE WAGNER FREE 



intercalary fine thread in each interspace ; the spirals pass over more obscure 

 transverse riblets, of about their own width, which ripple them, and on the 

 last whorl and a half give rise to squarish little-elevated nodules at the inter- 

 sections; the incremental lines are distinct, and the sculpture is practically 

 uniform over the whole shell ; most of the shell is comprised in the last 

 whorl, and the aperture is longer than half the shell ; outer lip gently arched, 

 and in the adult somewhat varicose behind the margin; suture very distinct, 

 not channelled ; aperture rather narrow, canal short and wide ; outer lip sim- 

 ple, with a row of denticles within behind the edge, but no lirje in the throat! 

 body with a thin, smooth callus ; pillar short, obliquely truncate, with an ob- 

 scure anterior plait and siphonal fasciole. Lon. of shell i8; of aperture ii ; 

 max. lat. of shell 9 mm. 



A number of specimens have been examined which appear fairly uni- 

 form in size and character. It is smaller and more globose than the typical 

 species, of which only one last whorl, wanting the spire, is known. This is 

 in the collection of the Academy of Sciences, Philadelphia. 



Genus PTYOHOSALPINX Gill. 



In 1826 (Hist. Nat. Eu. Merid., Moll., p. 172), Risso had named a genus 

 Tritia for a compound of Planaxis, Anachis, and various species of Nassa, 

 which he abandoned in favor of Planaxis Lamarck, though his Tritia in- 

 cluded more than Planaxis proper. Later, H. and A. Adams (Gen. Rec. 

 Moll. i. p. 122) revived the name Tritia for Nassas with elevated whorls, 

 reticulated thin shells, with moderate callus and a simple, non-varicose outer 

 lip. They included in it such forms as N. reticulata L., N. trivittata Say, 

 and cancellata Chemn. Conrad (Proc. Acad. Nat. Sci., 1862, p. 562) adopted 

 the name, which he used to cover the majority of American Miocene Nassida, 

 except the smooth forms, which he referred to Bidliopsis Ccnrad as a sub- 

 genus, though this is perhaps more nearly related to Connnclla. 



In 1866 Stimpson (Am. Journ. Conch, i. p. 61) proposed a new genus of 

 Nassidce, Ilyanassa, based on .A^. obsoleta Say. A feature not emphasized 

 by Stimpson, and perhaps correlated with the absence of the caudal cirri, is 

 the short, hardly recurved canal and the consequently feeble siphonal fasciole, 

 hardly separated from the base of the body-whorl on account of the absence 

 of the constriction which is so characteristic of the true Nassas. 



In 1867 (Am. Journ. Conch, iii. p. 153) Gill separated as a genus oi Bilc- 

 cinidce under the name of Ptycliosalpinx a species which had been described by 

 Conrad as Bticcimim altile, and subsequently referred by him to Tritia. The 

 following year Conrad {op. cit., p. 261) discussed Ptychosalpi?ix, vih\ch. he 

 referred to the NassidcE and discriminated two groups : i, those related to P. 

 altilis, and 2, those typified by P. porciiia, which have a slightly thickened, in- 

 ternally Urate outer lip. The latter group he denominated Paranassa, at the 

 same time recognizing Ilyanassa and Ptycliosalpinx as genera, and refer- 



