Notes on Radulcc. 



89 



Pleurocera eeevatum Say. Plate V, E. 

 Jaws as in subularc. 



Radula formula T \ + -|- -f \ + j^- 3 + t + i + tt (3~ 1 ~ 3) I 

 teeth generall}^ as in subulare ; the intermediate tooth has 

 five outer cusps instead of three, as in subulare ; the inner 

 lateral has 8 or 9 cusps, all large, and the outer layer has 

 1 1 small cusps. All of the teeth seemed to have well-developed 

 cutting points. 



PlvEUROCERA EEEVATUM JEWISH Lea. 



Radula in all respects like that of the type form. Lcwisii 

 has no claims to specific rank, as the writer has seen many 

 hundred specimens which show every gradation, from forms 

 almost smooth to strongly striated ones. 



Elimia livescens Menke. Plate V, F. 



Jaw similar to those of Pleurocera elevatum and subulare 

 (F, 4). 



Radula formula T V -f \ + \ + \ + \ + ^ -f~ tV (3-1-3); teeth 

 in general similar to those of the Pleuroceridse, excepting that 

 the central tooth has 4 small cusps on each side of the central 

 cusp instead of 3 ; the intermediate tooth has a medium sized 

 inner cusp, a very large, rounded cusp next, and three small, 

 rather sharp outer side cusps ; the first lateral has 8 denticles 

 and the second 10. The denticles are a little rounder in this 

 species than in the family previously mentioned. 



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