MADE BY DR. ANTONIO RAIMONDI IN PERU. 303 



depressions running to the sides ; the basal two-fifths of the surface is bent down 

 at a right angle; entire surface marked by small closely-placed ribs, between which 

 are small punctures ; these ribs are crossed by small concentric undulations, taking 

 the direction of the lines of growth. Smaller valve unknown. 



Figure. Natural size. 



Remarks. Allied to P. Boliviensis and P. Andii, d'Orb., in the expanded hinge 

 line, but differs from both in the beak being very small, instead of being large 

 and incurved, A marked character, by which it can be distinguished from all the 

 other known species of South America, is the sudden manner in which the basal 

 portion of the surface is bent down at a right angle. 



P. RETicaiiATUS, n. s., PL 42, fig. 13, 13a. 



Shell large, subquadrate ; hinge line not longer than the greatest width of the 

 shell ; sides and base broadly rounded ; base but very faintly emarginated. Lower 

 valve with a shallow median groove, bent down to nearly a right angle, but not 

 abruptly; beak small; upper valve nearly flat, slightly concave towards the margin 

 and slightly grooved in the middle of the basal portion. Surface marked by 

 numerous small ribs, crossed by concentric ridges of about the same size, producing 

 a cancellated appearance. 



Figures. Natural size. 



JRemarks. Allied to P. Inca, d'Orb , but less coarsely striate, more angulated 

 in cross section of the lower valve, from beak to base ; the beak is very much 

 smaller, and it wants entirely the traces of spines on the surface seen in that 

 species. 

 P., sp. indet. 



A small species, barely half an inch wide, too imperfect for description, from 

 the "Heights of Cullachaca, three leagues from Huanta." 



POLYZOA. 



RETEPORA. 

 R. FLEXUOSA, d'Orb., Amer. Merid., p. 5T, PL 6, fig. 6-8. 



CRINOIDEA. 



Two or three masses containing stems of crinoids, one of which is four inches 

 long, half an inch in diameter, and cylindrical. 



FORAMENIFEKA. 



FUSULINA, Fisch. 

 F. OYLiNDRiCA, Fiscli., Orjct. Gouv. Mosc, p. 126, PL 18, f. 1-5. 



