﻿PTYCHOBRANCHUS 



337 



Unio foremanianiis Lka, Pr. Am. Phil. Soc, II, 1842, p. 224; 

 Tr. Am. Phil. Soc, VIII, 1842, p. 247, pi. xxvii, fig. 64; 

 Obs., Ill, 1842, p. 85, pi. XXVII. fig. 64.— Chenu, 111. Conch., 

 1858, pi. XXVI, figs. I, la, i&.— SowERBY, Conch. Icon., XVI, 

 1866, pi. XXXVII, fig. 202. 



Margaron (Unio) foremanianiis Lea, Syn.. 1852, p. 23; 1870, 



p. 36. 

 Ptychobranchus foremanianiis Simpson, Syn.. 1900, p. 613. 

 Unio zvoodzi'ardius Lea, Pr. Ac. N. Sci. Phila., IX, 1857, p. 



170. 

 Unio ivoodwardianns Lea, Jl. Ac. N. Sci. Phila., IV, 1859, 



p. 199, pi. XXIII, fig. 82 ; Obs., VII, 1859, P- 17- pl- XXIII, fig. 



82. — ?Reeve, Conch. Icon., XVI, 1864, pl- xvi, 73. 

 Margaron (Unio) ivoodzvardianus Lea, Syn., 1870, p. ^6. 

 Unio z'elatus Conrad, Jl. Ac. N. Sci. Phila., 1853, p. 298, pi. 



xxvii, fig. 6. 



It will be seen from the above description and measurements 

 that I include a great variety of forms under the name fore- 

 manianiim. The types of this and woodzvardianu-s differ but 

 little in form, but are colored differently. Specimens from 

 the Call collection show the wavy rays and square blotches to- 

 gether. There are so many cross characters that I am not able 

 to designate any forms, which seem to be worthy of varietal 

 names. 



PTYCHOBRANCHUS TRINACRIUM (^ Lea ) . 



Shell long triangular, somewhat inequilateral, inflated, very 

 solid, with high, full beaks, whose sculpture has not been seen ; 

 posterior ridge hig^h, sharp, single, curved down in the middle, 

 and ending in a sharp point behind, just above the base line; 

 surface with irregular growth lines ; epidermis concentrically 

 wrinkled, dull, dirty yellowish-green with wide, darker green, 

 faint rays, which cover most of the shell, posterior slope al- 

 most truncated, lighter colored than the rest of the shell, with 

 a few faint, narrow rays ; hinge strong, the plate flat ; left 

 valve with two low pseudocardinals and two laterals, the 

 lower the stronger and club-shaped ; right valve with one pseu- 



