DESCRIPTION OF SPECIES BRACHIOPODA 300 



tions of the sinus of the pedicle valve, the small cardinal area, and the 

 extended hinge line. 



The shell to which Miller has given the name Spirifera novamexicana 

 from Lake valley, New Mexico, is certainly congeneric with this species 

 from the Fern Glen beds of the Mississippi valley and is a close ally, 

 although the two species are probably distinct. 



SPIRIFERINA SUBTEXT A White 

 Plate 13, figures 16-19 



1862. Spiriferina ? subtexta White, Proceedings of the Boston Society of Nat- 

 ural History, volume 9, page 25. 



1901. Spiriferina subtexta Weller, Transactions of the Academy of Science of 

 Saint Louis, volume 11, page 199, plate 20, figures 5-6. 



Description. — Shell of medium size, wider than long, the hinge line a 

 little shorter than or perhaps sometimes equaling the greatest width of 

 the shell, the cardinal extremities usually, perhaps always, a little 

 rounded. Pedicle valve with a prominent beak which is rather sharply 

 pointed and moderately incurved; cardinal area rather high, moderately 

 concave, with a narroAv delthyrium, not very sharply denned along the 

 cardinal margin; mesial sinus originating at the beak, becoming prom- 

 inent anteriorly and subangular in the bottom; lateral slopes convex, 

 very slightly or not at all compressed toward the cardinal extremities, 

 each marked by from seven to nine rounded plications, including those 

 bounding the mesial sinus, which are successively smaller in passing 

 toward the cardinal extremities; only one or two reach the beak, the 

 others terminating along the cardinal margin. Surface of the shell 

 marked by fine, regular, concentric, sublamellose lines of growth. Shell 

 structure punctate. 



The dimensions of a nearly perfect pedicle valve are: Width, 15.5 

 millimeters; length from beak to anterior margin, 10.5 millimeters; 

 height of cardinal area, 3.7 millimeters. 



Remarks. — This species is represented in the collection by incomplete 

 examples only, the pedicle valves being the best preserved. In the orig- 

 inal description of the species it is said to have "five or six prominent 

 plications on each side of the mesial fold and sinus," but the Fern Glen 

 examples possess from seven to nine plications upon each lateral slope, 

 although about six are usually all which can be said to be prominent. 

 The species is perhaps most closely allied to S. solidirostris, but it may 

 be distinguished at once by the absence of the median plication of the 

 fold and sinus. It may be distinguished from the associated 8. magni- 



