120 BULLETIN OF THE 



and, as these Cerions are quite variable and apparently local in their varia- 

 tions, it would not be at all surprising if this particular form should eventually 

 be shown to be wholly extinct. 



The following species were obtained by Professor Agassiz in a fossil condition 

 in the aeolian rock at 



Great Stirrup Cat. 



Cerion (Stropkiops) neglectum Maynard (also found at Andros). 



Gun Cat. 



Venus cancellata L. 



Cerithium algicola C B. Adams. 



Nassau (Queen's Stairway, low water level). 



Tritonidea auritula Link. 

 Hemitrochus Troscheli Pfr. 



The following apparently undescribed species of Cerion was also found in 

 the calcareous sand-rock at the W. quarry, top of Nassau ridge. 



Cerion (Maynardia) Agassizii n. sp 



Figures 9, 10. 



Shell large, cylindroconic, smooth for the genus, but varying as usual in the 

 number, sharpness, and presence of transverse ribs ; with eleven whorls, rather 

 closely appressed, irregularly transversely striated, the upper whorls more finely 

 and evenly, and the last third of the last whorl with stronger, sharp-edged, sparse, 

 elevated ribs; spiral sculpture none; umbilical chink deep, not perforate; 

 aperture ovate, pointed above, with the reflected margin wide, from the more 

 prominent inner edge, which is rounded, l)evelled away to the peripheral margin 

 which is sharp, the whole continuous as in Chondropoma ; the body with a thick 

 callus upon which the parietal tooth i^ situated, the tooth on the pillar lip less 

 prominent, somewhat elongated. Lon. of shell, 35 ; diam. above the aperture, 

 13 ; alt. of peristome axiallj% 13 mm. 



This shell resembles Strophiops maritima Pfr. most nearly, but differs from it 

 in its longer dental ridges, and in its wide, sharp-edged, and curiously bevelled 

 peristome. The sharp rugse behind the lip are very constant; those of S. ma- 

 ritima are relatively low and feeble. 



In this connection a few remarks are in place on the nomenclature of this 

 group. It was first separated from Turho by Bolten, who erected a genus 

 Cerion in 1799, which contained some extraneous forms, like most old genera, 

 but was based on Turho uva Liiine ; as is evident from the name, as well as 

 from Bolten's placing these shells first, and using their popular name " Bee- 



