ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 49 



habit), Virgularia multicalycina, Pteroeides rigidum, and Ft. pulchellum. 

 Attention is given to the great variability of the species of Clavularia 

 and Xenia, e.g. as to the number of rows of pinnules, the number of 

 pinnules, the bare streak on the tentacles, the spicules, and so on. 

 Mr. Crossland adds notes on the localities. 



Deep-Sea Alcyonarians from Indian Ocean.* — J. Arthnr Thomson 

 and W. D. Henderson report on a collection of Deep-sea Alcyonarians 

 made in the Indian Ocean by the Royal Indian Marine Survey Ship 

 ' Investigator.' The collection includes 86 species, of which 61 are new. 

 There are 6 new Stolon if era, 8 Alcyonacea, ?> Pseud axonia, 2'2 Axifera, 

 and 22 Stelechotokea. It has been found necessary to establish five new 

 genera — Stereacanthia and Agaricoides (separately described by J. J. 

 Simpson) in the family Nephthyidee, sub-family Siphonogorginge ; 

 Acantlwmuricm and Ccdkogorgia in the family Muriceidfe ; and 

 Thesioides in the family Kophobelemnonidte. 



Some of the new species are of considerable interest, e.g. a stalkless 

 form of Sarcophytum aberrans growing on a huge sponge spicule 

 (300 mm. in length by 2-3 mm. in breadth) ; ChironephtJiya macro- 

 spiculata with spicules over 8 mm. in length ; Protocaulon mdicutn, a 

 new member of the genus hitherto represented only by KolHker's 

 P. molle ; and so on. 



Embryos have been found in situ in eight cases, so that the list of 

 viviparous Alcyonarians is greatly increased. In the notes on geo- 

 graphical distribution the widespread occurrence of some deep-sea types 

 is well illustrated. Some of the epizoic animals are interesting, e.g. a 

 peculiar Solenogaster, Rhopalomenia gorgonophila (?), on Acamptogorgia 

 circium sp. n. 



Primary Septal Plan of the Rugosa.j — R. Gr. Carruthers finds from 

 a study of Zaphreiitis and other lower Palaeozoic corals that the primary 

 septal plan of these Rugosa is hexamerous, and is arrived at by an 

 insertion of bilateral pairs analogous to that occurring in the soft parts 

 of the rest of the Madreporaria. Thus, the Rugosa come into closer 

 association with modern corals, and the idea must be dismissed that 

 they are primarily tetramerous. 



Fragmental Fission in Metridium marginatum. J — M. L. 

 Hammatt finds that this occurs frequently in nature. From a study of 

 sections it is inferred that the body becomes bilaterally symmetrical 

 before the fragmental fission takes place, this occurring always, as far as 

 observed, on the larger side, and that the fragment thus cut off includes 

 body-wall (formed on the side next the parent by infolding of the 

 parent body-wall), and parts of directive and other mesenteries on one 

 side only of the plane of symmetry of the parent animal. The infold- 

 ing is essentially like the constriction which separates the Hydra bud 



* An Account of the Alcyonarians collected by the Royal Indian Marine 

 Survey ship ' Investigator ' in the Indian Ocean. I. The Alcyonarians of the 

 Deep Sea. Printed by order of the Trustees of the Indian Museum. Calcutta, 

 1906, xvi. and 128 pp., 10 pis. 



t Ann. Nat. Hist., xviii. (1906) pp. 356-63 (1 pL). 



X Amer. Nat., xl. (1906) pp. 583-91 (2 pis.). 



Feh. 20th, 1907 E 



