124 AMERICAN JOURNAL 



pi. 26, fig. 21, 22, 23 (?). Sby., Thes. Conch, vii, 352, 



pi. lii, fig. 50, 51, 52. 

 Waldheimia californica, Gray, Brit. Mus. Cat. p. 60, No. 



8. Cpr. Sup. Rep. Br. Assoc, p. 568 & 636. Cooper, 



Geogr. Cat. p. 3, No. 5. 

 Not Terehratula californica, Auct., = W. venosa, Sol. 



Hab. California. Catalina Island, 80 fms. Cooper. Smith- 

 sonian Cabinet, 19,395, Cp. 1093. 



Shell oval, thin, inflated, pale at the umbones, elsewhere of 

 a light reddish brown, darker toward the margin ; perforations 

 large,, oval, crowded, arranged in quincunx order externally ; 

 minute circular, very close together, internally. 



Margin straight, without perceptible curve or sinuation, 

 slightly angular at the anterior edge, giving a very slight appear- 

 ance of truncation. Valves nearly equally inflated. Beak of 

 the neural valve small, recurved, obliquely truncated. Foramen 

 small, entire, apical; the carination of the edge of the false 

 area encroaches on the perforation in a triangular point on each 

 side. False area small, narrow, smooth, roundly carinated at 

 the edge. Deltidia very short and wide, united. Lon., 1*9 in.; 

 lat., 1*6 in.; diameter, 1-2 in.; height of neural apex above the 

 opposite umbo, '15 in.; diameter of foramen, -1 in. Peduncle 

 very short and stout. Teeth of the neural valve short and stout. 

 Hinge line very slightly emarginate (for the cardinal process) 

 beneath the umbo, otherwise gently rounded. Teeth supported 

 by shelly plates beneath the hinge line. Cavity of the apex 

 infundibulate. Out of this cavity proceed two strong, but not 

 prominent, ridges, which radiate toward the angles of the ante- 

 rior edge of the margin, but become evanescent before passing 

 the central third of the shell. Between these ridges are two 

 others, one on each side, close to the median line, shorter and 

 less prominent than the first. There are faint indications of 

 others outside the two first mentioned, and these ridges, except 

 the first two, are variable in diff'erent individuals. Cardinal pro- 

 cess very inconspicuous. Cardinal plate broadly pentagonal, 

 centrally depressed. Septum not prominent, diminishing in height 

 from the edge of the plate forwards, and not extending more 

 than half the length of the shell ; point of attachment of the apo- 

 physes quite close to the plate. Apophyses start from the ante- 

 rior angles of the plate and give ofi" two curved slender crura ; 

 the haemal processes are very slender; septal processes still more 

 so; reflected portion quite broad, somewhat angulated behind, 

 giving ofi" two broad, thin lateral processes, which are attached to 

 the inner edge of the hsemal processes at the point from which 



