854 SUMMARY OF CUERENT RESEARCHES RELATING TO 



If, then, there is a close relation between the formation of an 

 endodermal layer by invagination and by immigration, we are next 

 led to ask, whicb is the more primitive arrangement ? Hackel 

 inclines to favour the former, Metschuikoff the latter ; for the 

 present it is impossible to decide between these doctors, and the 

 most jH-essing duty new is a renewed study of the early stages of 

 Thecidium. 



American Anthozoa.* — A. E. Verrill has a rejiort on the An- 

 thozoa dredged oif the east coast of the United States by the ' Blake,' 

 and those collected by the United States Fish Commission. A large 

 number of species, a considerable proportion of which are either new 

 or lately described by Prof. Verrill, were collected ; Lejpidisis is a 

 new genus, closely allied to Acarella, differing only in having the 

 external layer of small scale-like spicula, both in the coeuenchyma and 

 on the calicles. A new family — Chrysogorgidce — is instituted, the 

 species of which are " remarkable both for the elegance of the forms 

 in which they grow, and for the brilliant lustre and ojjaline and 

 iridescent colours of the axis, which in some species has the bright 

 emerald-green lustre of the most brilliant tropical beetles, and in 

 others is like burnished gold or polished mother-o'-j)earl." Irido- 

 gorgia is a new genus. The characters of the Primnoidae are 

 emended. Among the Gorgonidas Stenogorgia is a new genus, appa- 

 rently most nearly allied to Leptogorgia. A new genus is instituted 

 for Urticina nodosa, which receives the name of Aciinaiige, and two 

 new varieties of A. nodosa are described. Similarly Urticina ccllosa is 

 the ty2)e of a new genus — Actinostola. 



Hard Structures of the Fuiigiidse.f — Prof. P. M. Duncan, in a 

 continuation of his previous paper,| deals with several of the recent 

 genera of the subfamily Lophoserinre, an examination of which is 

 absolutely requisite before the classificatory position of many extinct 

 genera of corals can be decided. The genus Loplioseris is taken. as a 

 typical example, then Mceandroseris with collines limiting series of 

 calices is considered. Pachyseris follows as a most abnormal form, 

 the collines being in excess, and the genus Goscinarcea is examined. 

 Finally, the genera SiderastrcBa, Mendina, and Echinopora are exa- 

 mined. This involves some classificatory changes, and the intro- 

 duction of a new genus (Plesioseris — P. Australice = Mceandroseris 

 Australice), but the importance of the synapticula as a character of the 

 grouji is enhanced. 



Elevated Coral Reefs of Cuba.§— W. O. Crosby describes the 

 elevated coral reefs of Cuba, and draw's from them the apparently 

 well-sustained couclusion that they indicate a slow subsidence during 

 their formation, and hence, further, that Darwin's theory of the origin 

 of coral islands is the true theory. 



* Bull. Mus. Corap. Zool., xi. (1883) 72 pp. (8 pis.), 

 t Journ. Liun. Soc. Lond.— Zool. xvii. (1883) pp. 302-19 (1 pi.)- 

 X See this JouriKil, ante, p. G66. 



§ Pioc. Boston Soc. Nat. Hist. Cf. J. D. Dana in Amer. Journ. Sci., xxvi. 

 (1883) i)p. 148-9. 



