'7 - 



Subgenus Moerella Fischer. 

 TEIIII'A (MOEHEIIA) SIKPSOl'I Dell. 



Tel Una. ( I-Oerella ) si2;psoni Dall, 1900, Traxis. ?/agiier :?ree Inst. 

 Sci., Philadelphia, vol. Z, pt . 5, p. 1024, pi. 46, 

 fig. 12. 



Description. - "Shell small, inflate^,, equi valve, vei'^^ in- 

 equilate-^al, jolished; anterior dor fjal slo"pe rectilinear, anterior 

 end rounde ' , base convexly arouate ; posterior end very short 

 with the extremity bluntly pointed; beaks low, somewhat opistho- 

 gyrous, with a perceptihle la.!.rLle; hiixge norraal, pallial sinas 

 extending nearly to the anterior a-lductor sear, mostly confluent 

 belo'vv. Ion. 7, alt. 5, diam. 4 mm." 



"This form is v/hat "-'■o identified as T_. c une at a d ' Or b i gny . 

 but the latter is less inflated and less flexuous behind. T_. 

 sinpsoni sornetii:;es ap ears perfectly smooth, but other speoimens 

 show increment al sculpture." 



Type locality .- 3ov/den, Jamaica. 



Remarhs. - T_, sirapsonl is distinguished by its decidedly 

 inequilateral outline, convexity and sli-ht posterior constrict- 

 ion. The surface may be sculptured v/ it h fine concentric striae. 



