INVERTEBRATES. 77 



/Al'HKKNTIS ILI.1NOIEXSI8. (sp. DOV.) 

 PL IX, Figs. 4^4a. 



Corrallum very broadly turbiuate, cup oblique, surface marked 

 veral transverse undulating ridges and numerous longi- 

 tudinal stria-. Septal fossette deep and situated on the side of 

 least curvature; lateral fossettes narrower but distinct, separat- 

 ing The lamelhe into three well marked divisions, the two on 

 either side of the septal fossette consist of ten or eleven each, 

 and the other of twenty-eight, making thirty-eight to forty 

 primary lamelhe in the entire cup. 



This species was evidently sessile, and was attached near the 

 lower extremity to some cylindrical body, the scar of attach- 

 ment being visible on nearly all the individuals seen. 



Length of a large individual 2% indies : breadth of cup 2Vi 

 inches; depth of the same about 1 inch. 



Position and locality: Keokuk limestone. Warsaw, and near 

 Plymouth. Hancock Co., 111. 



Collector, A. H. Worthen. 



NO. 2.~>G2 of the Illinois State Museum. 



ZAPHRENTIS SPERGENENSIS. (sp. nov.) 



PL X, Figs. 8-8a. 



Corallum small, tnrbinate. straight or slightly curved at the 

 lower extremity. Surface striated longitudinally, and charac- 

 terized by numerous short spines irregularly distributed over 

 the entire corallum. Cup circular and proportionally rather 

 dec].: septal fossette well defined, with a narrow lateral fosset te 

 on cither side, separating; the lamella* into three divisions. 



Primary lamelke twenty-two, with about an equal number of 

 ondary order, the latter coalescing with the others at 

 about half the distance from the border of the cup to the cen- 

 ter. On each sidfi-of the septal fossette, and between that and 

 the lateral foe there are five primary and five secondary 



lamella-, that coalesce into one before reaching the center of 



the cup. 



Length of a medium size specimen % inch : breadth of cup, % 

 inch: depth of the same, 3 / 16 inch. 



