ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 471 



intermediate plates reduced to one, between the mouth-plates and infero- 

 marginals ; the papillae are isolated, strictly abactinal ; the tube-feet have 

 no calcareous deposits on the sucking-disk ; ihe ampullar are single ; the 

 iuterbrachial septa are practically absent. 



Revision of Genera of Bourgueticrinidae.* — Austin H. Clark has 

 revised the recent genera of this Criuoid family, which is among stalked 

 Crinoids the most widely represented. Genera occur in all the oceans, 

 and range from 62 to 2690 fathoms. Besides Rhizocrinus and Bathy- 

 crinns it is necessary to recognize Ilycrinus, Bythocriniis, and Democrinus, 

 and a new genus, Monachocrinus. In the new genus the arms divide 

 once, on the second post-radial ossicle (being ten or twelve in number) ; 

 all the post-radial ossicles are united in pairs by non-muscular articula- 

 tion ; and the basals are separate, or are fused into a solid ring which is 

 truncated conical, always longer than broad. 



Coelentera. 



Minute Structure of Actinians.f — Manuel Sanchez y Sanchez de- 

 scribes in Anemonia sulcata and Sagartia parasitica the minute structure 

 of the mesogloea with its complex array of fibres, often disposed in 

 glomeruli and spiral coils. He deals also with the glandular cells, the 

 nematocysts, and other elements of the ectoderm. 



Senonian Stromatoporella.| — Yvonne Dehorne describes from the 

 marine Senonian, near Martigues (Bouches-du-Rhone), massive colonies 

 of Stromatoporoids. The laminae and latilaminfe are very distinct, as 

 also the transverse partitions or tabulae. The characters correspond 

 well with the diagnosis Nicholson gave of Stromatoporella, and the 

 specific name S. haugi is proposed. Hitherto the genus has been 

 recorded from Primary rocks. 



Epithelio-muscular Cells of Hydra.§ — G. Roskine discusses these 

 elements, with two contractile basal prolongations which may attain a 

 length of 0'38 mm. Each prolongation consists of a fibril and 

 enveloping cytoplasm. The fibril consists of a delicate cylindrical 

 membrane enclosing a fluid plasma (kinoplasm). Schneider was wrong 

 in supposing that the fibril is made up of a number of still more 

 delicate filamentar elements, but there seems to be one elastic skeletal 

 filament in the interior of the kinoplasm. 



* Journ. Washington Acad. Sci., vii. {1917) pp. 388-92. 



t Boll. Soc. Espafi. Hist. Nat., xvii. (1917) pp. 217-21 (4 figs.). 



% Comptes Rendus, clxv. (1917) pp. 67-70. 



§ C.R. Soc. Biol. Paris, Ixxx. (1917) pp. 365-6. 



