1881.] NATURAL SCIENCES OF PHILADELPHIA. 259 



1850. Dichocr. Striatus Ow. and Sh. Jour. Acad. Nat. Sci. Phila. vol. ii, Pt. i, j 

 also U. S. Geol. Kep. Iowa, Wis. and Minn. p. 590, PI. 5 A, figs. 10 a, b. 

 Upper Burlington limest, Burlington, Iowa. 



9. TALAROCRINTJS, nov. gen. , 



{ralapog a small basket, Kplvov a lily.) 



Syn. DicTiocrinus Shumard (in part) 1860 (not Miinster). Trans. 



Acad. Sci. St. Louis. 

 Syn. Dichocrinus Cass, and Lyon (in part) 1860. Proc. Am. Acad, 



Arts and Sci., v, p. 16. 



Among the species described by Shumard imder Dichocrinus 

 there are two, which differ materially from that genus and from 

 Pterotocrinus, with which they are nearest related. Meek and 

 Worthen, in their generic description of Pterotocrinus (Geol. Rep. 

 111., ii, p. 290), recognized more than specific differences between 

 the form represented by Shumard's Dichocrinus cornigerus and 

 D. sexlobatus, and the genus Pterotocrinus with which these two 

 species had been identified, and thej' proposed either to divide the 

 genus into two sections, or to separate the above species from it 

 sub-generically. Shumard afterwards and also S. A. Miller, in 

 their catalogues placed both species under Pterotocrinus. 



Wetherby (Cin. Journ. Nat. Hist., 18t9, Apr. number) on the 

 other hand, refers the above species to Dichocrinus and considers 

 them altogether di!i*"nct from Pterotocrinus. In the latter con- 

 clusion he is undoubtedly correct, but we cannot see that their 

 relations to Dichocrinus are any closer. They evidently form a 

 little group by themselves, which in nature occiapies a place 

 between the two genera, forming a connecting link between them. 

 We propose for this group the generic name Talarocrinus with 

 D. cornigerus Shum. as the type. 



Generic Diagnosis. — General form of body ovoid ; composed 

 of heavy plates. Calyx subconical ; plates convex, deeply im- 

 pressed at the suture lines, and hence more or less protuberant ; 

 surface smooth. 



Basals two, pentagonal, precisely alike, the suture running from 

 the posterior to the anterior side. First radials large, quadran- 

 gular, nearly as wide as high, aranged in line with the first anal 

 plate, which is as large or larger than the radials, and of similar 

 form. The upper edge is excavated, but not semicircular, there 



