998 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Eypocrinus is distinctly an embryonic type, having a monocyclic base, 

 imperfectly developed radial plates, small sac, embryonic arms, and 

 no pinnules. 



A study of Stephanocrinus has convinced the authors of the inap- 

 propriatcness of regarding the Crinoids, Cystids, and Blastoids, as 

 distinct classes; while it is, they think, unquestionably a Palaeo- 

 crinid, it has the oral and anal pyramid of certain Cystids, and in 

 the general habitus and the position of its ambulacra it agrees with 

 the Blastoids. It must bo placed in the Larvifonnia, among which 

 it forms the type of a new family. 



In a note on the underbasal and top stem-joint of Neocrinoidea 

 and Pakoocrinoidea Messrs. Wachsmuch and Springer suggest that 

 the inner plate of Stemmatocrinus, Cupressocrinus, and allied genera, is 

 not a stem-joint, but an anchylosed underbasal disc ; when examined 

 from the inner side of the calyx, the plate is seen to form a part of 

 it, and to rest against the lateral, and not tho outer faces of the 

 basals. 



Coelenterata. 



Classification of the Medusae.* — Prof. C. Claus resumes some of 

 his previous generalizations on the classification of the Medusae, and 

 subjects some of Hiickel's conclusions to a somewhat polemical 

 criticism. The system of Acraspeda which he elaborates is as 

 follows : — 



I. Tetrameralia — with quadrate symmetry. 



I. Order : Calycozoa — including the families Depastridee, Lucer- 

 naridse. 

 II. Order : Marsupialia — including the family Charyhdeidae. 



II. Octomeralia — with octagonal symmetry. 

 III. Order: Discophora. 



1st Sub-order — Catammnata; — including the families Peri- 



pliyllidse and Epliyropsidse. 

 2nd Sub-order — Acatammnia. 



1. Monostomeaa — including the families Pelagidse, Cya- 



neidse, Discomedusidse, Sthenonidee, 

 Aureliadse. 



2. Rhizostomeae — including the families Achirizidse, 



Cassiopeidse, Cepheidse, Lychnorhizidse, 



Stomolophidse, Rhizostomidse, Cato- 



stylidse, Leptobrachidee. 



The Peripliyllidse, with which he includes Pericolpa and the 



Ephyropsidee (including Linergidse) are grouped as the first sub-order 



of Discophora, under the Catammnata. The principal characters of 



this sub-order consist in the persistence of the septal knots ("Septal- 



knoten "), in the presence of 16 pararadial coalesced bands, the " Lap- 



penspangen," and in the resulting configuration of the exumbrella and 



of the peripheral gastral system. The simple and primitive form of 



the oral tube is also noteworthy. 



* Arbeit. Zool. Inst. Univ. Wien (Claus), vii. (1886) pp. 97-110 (4 figs.). 



