BRACHIOPODA — TELOTREMA TA. 315 



finely punctate. Numerous, irregularly scattered, small spines 

 present. 



Kaskaskia of Kentucky, Indiana, Illinois. Upper Devonic? 

 Mississippic and Carbonic of Nevada. 



325. S. kentuckiensis (Shumard). (Fig. 396.) Upper Carbonic. 



Small, varying in outline from subcircular to transversely pro- 

 duced. Differs from S. spinosa in its smaller size, pointed hinge 

 extremities and greater number of plications (10-18). 



Widely distributed in North America. 



Fig. 396. Spiriferina kentuckiensis (Ind. Geol. Surv.). 



CIII. Spirifer Sowerby. 



Usually much wider than long, radially plicate or striate, crossed 

 by concentric growth lines. Hinge line generally long and straight. 

 Usually a median sinus present on pedicle valve and corresponding 

 fold on brachial. Pedicle valve with moderately high area and 

 open delthyrium, the margins of which are prolonged into stout, 

 simple teeth supported by dental lamellae. A calcareous brachid- 

 ium in the form of a double spire, whose apexes are directed 

 tov/ard the cardinal extremities nearly fills the cavity of the shell. 

 Jugum incomplete. Cardinal process low. A median septum at 

 times present in one or both valves. Siluric-Carbonic. 



A. Plications absent. Strong radiating striae present 326. S. radiates. 



B. Plications present *. 



* Plications covering entire surface f. 



f Plications arranged in bundles or groups (fasciculate) \. 



\ Plications of nearly equal size 371. S. striates. 



% Plications of unequal size 372. S. cameratus. 



f Plications not fasciculate {J. 



XX Plications on fold and sinus nearly or quite like those on rest of 



shell 1. 



1. Shell large, ventricose a. 



(i . Length exceeding breadth, very large 366. 6". grimesi. 



it. Breadth exceeding length i / . 



i / . Sinus prominent, much produced anteriorly a / . 



a'. Beaks of both valves very prominent and arching. 



346. S. divaricates. 



a / . Beak of pedicle valve much more prominent than 



that of brachial 368. S. logani. 



