130 ANNALS NEW YORK ACADEMY OF SCIENCES 



1894. Productus cequicostatus. Hall and Clarke, "Introduction to Study of 

 Brachiopoda," pt. 1, pi. 22. figs. 11. 12. 

 Coal Measures : Nebraska. 

 1900. Productus corn var. americanus. Beede. Univ. Geol. Surv. Kansas. Rept, 

 vol. 6. p. 77. pi. 11, fig. 2. 

 Upper and Lower Coal Measures: Kansas City. Eudora, Anderson Co., 

 Kansas. 

 190G. Productus corn var. americanus. Woodruff, Nebraska Geol. Surv., Rept., 

 vol. 2, pt. 2, p. 270. pi. 11. fig. 2. 

 Carboniferous: Louisville. Nebraska. 



Sbell of tbe cora type, rather large, widest at the hinge, more or less strongly 

 transverse. In the immature condition, this form closely resembles P. cora 

 itself, being strongly convex and more nearly quadrate. In the later stages, 

 the growth is more spreading, especially at the sides, and the margins are 

 flatter. Two varieties can be distinguished, one which is narrow and more 

 highly arched and the other transverse and less convex. In the mature condi- 

 tion, also, the ventral valve becomes elevated and angular along the median 

 line. Correlated with this character is an inflection of the anterior margin 

 making a deep sinus in the outline. A sinus or depression in the shell itself is 

 naturally absent. 



The surface is marked by tine. even, rigid, rounded costa? having the 

 peculiarities of those of P. corn. As in that species, the costa? bifurcate freely 

 and sometimes this takes place simultaneously all around a shell, so that for a 

 time the striation is much finer about its margin than over the earlier portion. 

 In connection with the carina, the costa? in the immediate neighborhood fre- 

 quently bend inward toward the median line which in some cases appears to 

 have been without costa 3 . A few large plications are found at the sides near 

 the hinge, but they seldom pass entirely across the sbell. They are apt to be 

 more persistent on the dorsal valve, however, than on the ventral. Spines are 

 scattered over the surface of the ventral valve, but they are usually small, not 

 causing nodes on the costa 1 , and they are liable to be overlooked when broken 

 off. They appear to be few in number. A row of larger ones is developed 

 along the cardinal line. 



As the synonymy shows, this species lias several times appeared in the 

 literature under the title of Productus cequicostatus, but a careful reading 

 of Shumard's description leaves little doubt that P. cequicostatus was a 

 different species and one more closely similar to P. cora itself. 



Horizon and locality : Found in the Wewoka formation, but the type 

 specimens are from Kansas. 



Pugnax osagensis var. percostata var. nov. 



This form is more abundant in the Wewoka formation than the typical 

 variety. In a general way, the specimens referred here agree with P. osagensis, 

 the only difference of importance being tbe more numerous plications which 

 are also smaller and more angular. Of these there are usually five fairly 



