430 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Species of Pectinatella from Japan.* — A. Oka describes 

 Fectinatella davenporti sp. n., the third known species of this genus. The 

 stocks of this Polyzoon are rarely more than 1 cm. in size ; for the most 

 part they are isolated. Blending of numerous colonies into one large 

 gelatinous mass, as takes place in the other two species, has not been 

 observed. A distinctive feature of the individual zooid is the short 

 stomach with few longitudinal folds. The statoblasts also are quite 

 characteristic. 



Fresh-water Polyzoa of India.f — N. Annandale gives a list of the 

 species, eleven in all, known to inhabit fresh or brackish pools in India. 

 Valuable critical notes, and records of habitat and distribution, are 

 added. The species belong to the genera MembraiU2wra, VictoreUa, 

 Hislopia, Pahidicella, Plumatella, Lophoinis, and Pectinatella. 



Pectinatella magnifica Leidy in Berlin. $ — W. Weltner records the 

 interesting fact of the occurrence of this native of North America at 

 Berlin, in the Havel of Spandau. He finds that it may multiply, as 

 Cristatella and Lophopus do, by the separation of masses to form new 

 colonies. A prolongation bearing polypides grows out from the parent, 

 increases in size, and about the fourth day separates to live independently. 



Minute Structure of Alcyonidium mytili.§ — S. Silbermann gives 

 an account of the histology of all the leading structures of this Polyzoon, 

 e.g. body-wall, tentacles, brain ganglion, alimentary canal, etc. A state- 

 ment of the course of degeneration of the polypides, and subsequent 

 formation of the sex-products, is also given. On the question of the 

 specific identity of A. mytili and Sarcochitum polyoum, suggested by 

 Hassall, it is pointed out that the many papillae and protuberances upon 

 the latter, and absent in the former, are sufficient to separate the two 

 forms. They are, however, together with Cycloum papillosum, probably 

 closely related. 



Trichoplax, a Planula.jj — T. Krumbach gives an account of observa- 

 tions which lead him to conclude that Tricfioplax, hitherto classed as a 

 Mesozoan, is the planula of the Hydromedusan Eleutheria, but whether 

 it occurs as a normal phase of development, or otherwise, has not been 

 made out. 



Echinoderma. 



New Deep-sea Starfishes.lf — H. Ludwig gives a preliminary account 

 of Pectinidiscus amice g. et sp. n., in the family Ctenodiscinse (East 

 African Coast), and the following in the family Porcellanasterinae — 

 Thoracaster magniis sp. n., four new species of Styracaster, Ghunaster 

 scapanephorus g. et sp. n. (South of Sumatra), Eremicaster g. n., Por- 

 cellanaster (s. str.) vicinus sp. n., and Albatrossaster nudus sp. n. 



* Zool. Anzeig., xxxi. (1907) pp. 716-18. 



t Journ. and Proc. Asiatic Soc. Bengal, n.s. iii. (1907) pp. 83-93 (4 figs.). 



J Arch. Natur., 1906, pp. 259-64 (3 figs.). 



§ Tom. cit., pp. 265-310 (2 pis.). 



li Zool. Anzeig., xxxi. (1907) pp. 450-4. 1 Tom. cit., pp. 312-19. 



