INVERTEBRATES. 73 



ZAPHRENTIS SPINULOSA, Edw. and Haime. 



PL X, Figs. 6-tia. 



Coral turbinabe, moderately elongated, a little curved and 

 slightly distorted, with a few irregular external ridges; epitheca 

 thin and on the lower portions ornamented with little sub- 

 spiniform points; cup circular, moderately profound; fossette 

 moderately developed, situated near the wall but in a variable 

 position from conforming to the curvature ; lamellae about thirty, 

 very feebly curved near the septal fossette, with an equal number 

 of rudimentary lamellae. 



Height of an average size specimen, 1% inches ; breadth of cup, 

 about % to % inch. 



Position and locality: Chester, 111., Chester limestone. 



Collector, A. H. Wort-hen. 



No. 2559 of the Illinois State Museum. 



ZAPHRENTIS CHESTERENSIS. (sp. nov.) 



PL IX, Figs. 3-3a. 



Corallum elongated, moderately curved, gradually and regu- 

 larly tapering; calyx circular, not deep, fossette deep, and 

 situated on the side of shortest curvature. Lamellae in four 

 divi visions, the two on either side of the fossette to the number 

 of seven or eight coalesce before reaching the bottom of the 

 calyx. On each side of the strong septum opposite the fossette, 

 there are twelve or thirteen lamelke that extend singly to the 

 bottom of the cup. Surface slightly rugose, with traces of short 

 spines scattered irregularly over it. 



This is a vnricty of Z. si>inuloxa, K. and H., but may be 

 distinguished by its more elongated and symmetrically 

 form, and greater number of lamellae. 



Height 2 11 /]; diameter of calyx, 1% in. 



Position and locality: Chester limestone, Monroe and Ran- 

 dolph counties. 



Collector, A. H. Worthcu. 



Xo. 2560 of the Illinois State Museum, 



1) 



