446 L. Agassiz on the Echinodermata. 



13. Eugeniacrinus, Mill. (Symphytocrinus, Keen.)— Pedicel 

 rounded and smooth, formed of a small number of long articulations. 

 The base of each ray is composed of an inflated and proportionally 

 large piece ; all these pieces (there are generally five, but sometimes 

 only four) are connected together. It is not known how the rays 

 ramify. All the species are fossils from the jura. (E. mespiliformis, 

 Goldf., from the greywacke appears to have distinct generic cha- 

 racters.) 



E. caryophyllatus, Goldf. — E. compressus, Goldf. — E.Nausmanni, Rcem. 

 E. Noferi, Munst. — E. moniliformis, Munst. — E. nutans, Goldf. — E. piri- 

 formis, Munst. — E. quinquangularis, Mill. 



14. Solacrinus, Goldf. — At first sight, this genus does not ap- 

 pear to differ from Eugeniacrinus, by the side of which Goldfuss 

 placed them, except by the presence of small distinct articulations 

 between the base of the rays. However I believe it to be more nearly 

 allied to Comatula, and especially to the genus Glenotremites. The pe- 

 dicel is very short, rounded at its extremity, which makes me think 

 that these animals were free, and that the impressions which we no- 

 tice on the pedicel were the points of insertion of rays similar to 

 those which the Comatula bear on their dorsal surface. But not 

 having had opportunity to examine them myself, I leave them provi- 

 sionally in the place which the author of this genus has assigned to 

 them. All the species are fossils from the jura. 



S. costatus, Goldf. — »S. scrobiculatus, Munst. — S. Jcegeri, Gold. 



15. Rhodocrinus, Mill. — Pedicel more or less rounded, tra- 

 versed by a pentagonal canal, base of the rays formed of five small 

 articulations, each topped by two other rather larger pieces, after 

 which follow other laminae similar but less regular and smaller, which 

 form underneath the visceral cavity, from the edge of which proceed 

 five rays which branch out like those of the Pentacrini. The spe- 

 cies are fossils from the greywacke and carboniferous limestone. 

 (The Rh. echinatus, Schlot., with spiny pedicel from the jura, appears 

 to form a distinct genus, the characters of which I am yet unable to 

 indicate, being unacquainted with the structure of the rays.) 



Rh. canaliculars, Goldf. — Rh. gyratus, Goldf. — Rh. quinquepartitus, 

 Goldf. — Rh. crenatus, Goldf. — Rh. vents, Mill. — Rh. quinquangularis, Mill. 



16. Actinocrinus, Mill. {Rhodocrinus, Keen.) — This genus differs 

 from the preceding by its pedicel being pierced by a round canal ; 

 the laminae of the disc which surround the sides of the visceral cavity 

 are more numerous and less regularly disposed. The species are 

 fossils from the greywacke and carboniferous limestone. 



