ZOOLOGY. 575 



V. ECHINODERMS. 



GENERAL. 



Ludwig(H.) Morphologisclie Studien an Echinodermen. ii Bd. 2. Hft. Mit. 



SPECIAL ORDERS. 



Crinoids. 



Bell (F. Jeffrey). An attempt to apply a method of formulation to the species of the 



Comatulidae ; with the description of a new species. With 1 pi. Proc. Zool. Soc. 



London, 1882. Pp. 530-586. Abstr. in Journ. B. Mia-osc. Soc, (2,) vol. ii, p. 791. 

 Carpenter (PbiUip). On the Relations of Hyrocrinus, Bcerocrinus, and Hybocystites. 



With 1 pi. Quart. Journ. Geol. Soc, London, vol. xxxviii, p. 298-312. 

 Wachsmuth (Ch.) and F. Springer. Revision of the Palseocrinoidea. Part III. Proc. 



Acad. Nat. Sci., Phila., 1882. 



Echinoids. 



Kohler (R.) Siir quelqnes essais d'hybridation eutre diverses especes d'Echiuoidfees. 

 Compt. rend. Acad. Sci., Paris, t. 94, pp. 1203-1205. 



Ophiuroida. 



Verrill (A. E.) Restoration of the Disk in Ophiurans. Amer. Journ. Sci., (3,) v. xxiii, 

 p. 408: Ann. <f- Mag. Nal. Hist. (.5,) v. ix, pp. 476-477. 



Aaierioids. 



Ludwig (Hub.) Entwicklungsgeschichte der Asterina gibbosa. Forb. Mit 8 Taf. 



Zeitschr. f. tviss. Zool., 37 Bd., pp. 1-98. 

 Perrier (Edmond.) Sur une Ast^rie des grandes profondeurs de I'Atlantique, pourvue 



d'un p^doncule dorsal ICaulaster pedunculatus, n.] Compt. rend. Acad. Sci. Paris, 



T. 95, pp. 1379-1381. 



Holothurioids. 



Jourdan (Et.) Sur les organes sexuels males et les organes de Cuvier des Holothu- 

 ries. Compt. rend. Acad. Sci. Paris, t. 95, pp. 252-254. 



Hyhrization among Ecliinoids. 



Mr. R. Kohler lias made "some experiments in hybridization between 

 diiferent species of Echinoidea," and found that cross fecundations "are 

 possible between different species of Echinoidea, and that between very 

 wide limits," as, for example, between a Spatangus and a PsammecMnus, 

 which he thought (without sufficient justification) were at least as differ- 

 ent as two mammals of allied orders. "And if the plutei obtained by 

 crossing between regular Echinoids do not appear to differ much from 

 the legitimate plutei of the type functioning as female in the experi- 

 ments, there are certainly well marked differences between a legitimate 

 pluteus of Spatangus and a hybrid pluteus of Spatangus and Psamme- 

 chinus." He calls special attention to the fact that " because the ova 

 of a species when fecundated by the spermatozoidsof another species ar- 

 rived at the state of pluteus, it does not follow that the converse is true. 

 Thus, the ovules of Spatangus are perfectly fecundated by the sperma- 

 tozoids of Psammechinus, but the ovules of the latter, subjected to the 

 influence of the semen of the Spatangus, remain for the most part in- 

 tact, while the rest scarcely reach the blastula stage." 



