LAMELLIBRANCHIATA. 483 



SOLEN. 

 S. Genus P A L .E S L E N , n. s. g. 



SoLEN (Pal^osolen) siliquoidea. 



PLATE LXXVIII, FtG. 33. 



Orthoiwia gUiqtioidea, Hall. Prelim. Notice Lamellibi-anchiata, 2, p. 89. 1870. 



" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 78, fig-, 33. 1883. 



Shell solenoid ; length more than four times the greatest height. Basal and 

 cardinal margins sub-parallel. The cardinal margin is straight and the basal 

 margin extends slightly downward posteriorly. Posterior extremity abruptly 

 truncate, gaping. Anterior end very short, straight on the cardinal line and 

 regularly rounded below. 



Shell sub-cylindrical. Valves regularly convex their entire length. 



Beaks sub-anterior, low and undefined. Umbonal slope marked by a shal- 

 low, indistinct diagonal groove, which is merged in the general convexity 

 before reaching the post-inferior extremity. Post-cardinal slope wide, 

 slightly undulated. 



Surface marked by fine concentric striae, the remains of which are pre- 

 served in the cast. 



The specimen described has a length of G5 mm., a height at the beak of 

 10 mm., and at the posterior end of 14 mm. 



This shell was originally placed under the genus Orthonota from its general 

 similarity in form, and from a disinclination to propose another generic name ; 

 but a proper limitation of that genus requires the separation of this species. 



This species difters from any of the preceding in the regularly convex, cylin- 

 drical form of the entire shell, and the gaping posterior extremity. 



Formation and locality. In the arenaceous beds of the Hamilton group in the 

 southern part of Schoharie county, N. Y. 



