44 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



ture and for the large opening in tlie front of the calcareous wall of 

 tlie Membraniporidas, &c. 



The author proposes to divide the Cheilostomata into two tribes 

 according to the character of the ectocyst, adopting the view of most 

 embiyologists that the ectocyst of the larva produces the calcareous 

 test of the zooecium and the endocyst the polypide. We have then 

 the two divisions of Monodermata (simple ectocyst) and Diplodeb- 

 MATA (double ectocyst). 



It is intended at some future time to examine all the families of the 

 Diplodermata, but at present the author only deals with one which 

 he calls Onychocellidte. The type of this is Memhranipora angulosa, 

 which he re-names OnycJiocella marioni Jull., considering the onycho- 

 cellaria to be of great classificatory value. The family is divided 

 into eight new genera ; these, however, seem largely based upon the 

 figures in D'Orbigny's ' Paleontologie Francjaise,' and we think that 

 Dr. Jullien would sometimes find that the older portion and the 

 growing part of the same sjiecimen would have to be placed in 

 separate genera, as the shape of the zooecia and of the opesia is 

 largely used as a generic character. 



This is certainly a siiggestive paper, and although all the con- 

 clusions of Dr. Jullien may not be accepted it may lead to several 

 important characters receiving more attention, and the classification 

 now in use may be much modified thereby. 



New Type of Polyzoa— Cephalodiscus.* — Prof. M'Intosh describes 

 a new type of Polyzoa allied to Allman's Rliabdopleiira dredged in 

 the ' Challenger ' expedition, for which the name of Ceplialodiscus 

 dodecalophus is proposed. 



It differs from Bhabdopleura in regard to the coenoecium, in the 

 much greater size of the buccal shield, in the remarkable branchial 

 or tentacular plumes, in the structure of the pedicle, and in the 

 perfectly free condition of the polypides. Cephalodiscus and Bhabdo- 

 pleura agree in the absence of the calyciform membrane connecting 

 the bases of the tentacles, in the position of the mouth, which opens 

 ventrally behind the buccal shield, in the general structure of the 

 alimentary canal, and in the position of the anus. The development 

 of the young buds is similar. Both connect the ordinary Polyzoa 

 with Phoronis. Cephalodiscus naturally falls under Professor Allman's 

 section Polyzoa Aspidophora, and further demonstrates the correctness 

 of that author's oi^inion in regard to the systematic position of these 

 anomalous forms. 



The following is the diagnosis of the genus : — Coenoecium con- 

 sisting of a massive irregularly-branched, fucoid secretion resembling 

 chitine, hispid with long spines of the same tissue, and honeycombed 

 throughout by irregular apertures, channels, and spaces, in which the 

 separate and independent polypides occur singly or in groups. 



Lophophore richly plumose, with an enormous buccal shield and 

 large oral lamella, the mouth opening between the two. Anus on 

 the interior dorsal prominence, behind the plumes. Two large eyes 



* Anu. aud Mug. Nat. Hist., x. (1882) Y>p. 337-48. 



