BRACHIOPODA — TELOTREMATA. 297 



Helderbergian and Oriskanian of New York, Pennsylvania, 

 Maryland, Missouri, Quebec. 



LXXXIV. Rhynchopora King. 

 Resembles Camarotoecliia but differs externally in its punctate 

 shell structure. Mississippic. 



281. R. pustulosa (White). Mississippic. 

 Small, biconvex. Front broadly 



rounded. Cardinal slopes straight- 

 ened. Surface marked by 16-22 

 simple rounded plications five of 

 which are on the sinus and fold each. 

 Kinderhook of Iowa, Utah, New 

 Mexico. 



LXXXV. Rhynchonella Fischer 



de Waldheim FlG - 3 6 9- Eatoma peculiaris 



(Pal. N. Y., III.). 

 Rostrate, subpyramidal. Apex 



of pedicle valve but slightly incurved. Prominent median sinus 

 present on pedicle valve and fold on brachial in typical species. 

 In pedicle valve deltidial plates conspicuous; dental lamellae pres- 

 ent. In brachial valve a median septum present ; no cardinal 

 process and no arm supports except crura. Surface radially pli- 

 cated. Ordovicic(?)-Eocenic. 



A. Plications present only upon anterior portion of shell 285. R. ccquiplicata. 



B. Plications present upon entire shell *.. 



* Outline subtrigonal. Shell less than I inch wide I. 



1. Median sinus bearing less than 6 plications 286. R. gnathophora. 



I. Median sinus bearing 6 or more plications a. 



a. Surface with 20 to 25 plications 283. R. hiibbardi. 



a. Surface with more than 20 to 25 plications i / . 



1/. Shell small, a half inch or less in width ... 282. R. eurekaensis. 

 i / . Shell of medium size, more than a half inch in width. 



284. R. myrina. 



282. R. eurekaensis Walcott. (Fig. 370.) Mississippic. 

 Small, subtrigonal in outline. Width and length subequal. 



Brachial valve slightly deeper than pedicle. Pedicle valve with a 

 prominent, projecting beak and with a rather shallow sinus that 

 forms about half the width of the shell anteriorly. Brachial valve 

 with a slight median fold; umbo strongly incurved. Surface of 

 each valve with 40 to 50 round, simple plications. 

 Nevada; Arkansas? (Spring creek limestone). 



