MIOCENE MOLLUSCA AND CEUSTACEA. 81 



Genus SYNDOSMYA Reclus. 



Syndosmya? nuculoides. 



Plate XV, figs. 7-9. 



Amphidesma nuculoides Conrad : A m. Jour. Sci., 1st. ser., vol. 41, p. 347 ; Miocene Foss., 



p. 73, PI. XI, fig. 6. 

 Abra miculoides Con.: Acad. Nat. Sci. Phila., 1862, x>. 574; Meek, Check List, p. 11. 



"Qvate, convex, very inequilateral, with very regular minute concen- 

 tric lines, posterior side subcuneiform ; extremity acutely rounded; lateral 

 teeth obsolete." (C'onrad.) 



The specimen which I have refen-ed to this species is about one-half 

 larg'er than Mr. C-onrad's figiu'e, but in other respects closely resembles it in 

 outline and general features. The shell is rather elongate-ovate, and mod- 

 erately convex, and extremely thin and delicate in texture. The beak is 

 small, situated rather within the anterior third of the length, behind 

 which the shell is narrowe<l, tlie jjosterior end being more narrowly rounded 

 than the anterioi-; l)asal and cardinal margins subparallel; surface with very 

 fine concentric lines only, and with a very faintly defined, oblique, mesial 

 sulcus. Internally there is a single, moderately strong, direct tooth beneath 

 the beak, with a deej), wi<le pit hi front, in the right valve, and a slight pro- 

 jecting lamellar tooth near its extremity. No appearance of a posterior 

 lateral tooth can be seen. Muscular imprints very faint, and pallial sinus 

 shallow and obscure. It is not an Abra, as there are no lateral teeth. 



Locality: Sliiloh, N.J. From the collection of the National Museum; 

 but only a single right valve observed. 

 MON XXIV 



