1886.] NATURAL SCIENCES OF PIITLADELPinA. 185 



The latter has a turbinate calyx, underbasals (observed by Bey- 

 rich not by H. v, Meyer), an apparently round stem; ten arms 

 which are not very closely folded, composed of cuneiform flat 

 joints, and pinnules which are alternately arranged. The totally 

 different form of the dorsal cup seems to us sufficient to warrant 

 the generic separation. L. v. Buch's t3"pical specimen came from 

 Recaoro, Italy, and was supposed by Beyrich to be identical with 

 certain fragments which had been discovered in the Trias of 

 Upper Silesia, too imperfect, however, for critical comparison. 

 From this locality a more perfect specimen was found lately by 

 Mr. n. Kunisch, who figured and described it in the Zeit- 

 schrift d. deutsch. geol. Gesellsch. Jahrg., 1883, under the title 

 " Ueber den ausgewachsenen Zustand von Encrinus gracilis 

 Buch." We cannot altogether agree with Mr. Kunisch in his 

 views. The Silesian species is, in our opinion, essentially differ- 

 ent from the Italian one. The column is pentagonal in place of 

 circular; the arms rounded, angular at the outer face, and the 

 pinnules are given off alternately from every second joint, every 

 other one being united by syzygy ; contrary to the typical species, 

 which has flat arms, cuneiform joints, and of which every joint is 

 pinnule-bearing. The distinctions are so obvious that a specific 

 separation is necessary, and we propose for the Silurian species 

 the name Dadocrinus Kunischi. To explain the diversity in the 

 arm-structui-e by individual growth is at variance with the obser- 

 vations made upon recent as well as fossil Crinoids. We agree 

 that the arms undergo important modifications in their growth, 

 but we do not find cuneate arm joints turning into quadrangular 

 ones, though frequently the opposite is the case ; nor that single 

 joints are undergoing segmentations and are uniting again by 

 syzygy. The angles of the column in Dadocrinus Kunischi are 

 directed interradially, thus proving theoretically the base to be 

 dicyclic, which could not be ascertained from the specimen. 

 We propose the following : 



Bevised Generic Diagnosis. Form of dorsal cup obconical. 

 Underbasals small, covered by the column ; basals forming an 

 elongate hexagonal cup. Radials comparatively smaller than in 

 Encrinus, but yet twice as large as the basals. Brachials in 

 number, form and articulation as in Encrinus. Arms long, uni- 

 serial, composed of single or compound joints, the latter united 



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