ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 189 



Ccelentera. 



Madreporaria from Persian Gulf.* — Ruth Harrison reports on a 

 collection made by F. W. Townsend. The occurrence of a recent 

 Trematotrochus {T. zelandiae Duncan) is worthy of special attention. 

 Hitherto the genus has been known from seven fossil and one recent 

 species from Australia and Australasian seas, and it is remarkable to find 

 it appearing in so remote a locality as the Persian Gulf. More remark- 

 able still is the fact that this very species has already been described 

 from Cook's Strait, New Zealand, by Prof. Martin Duncan, under the 

 name of Conocyathus zelandise. Part of the interest of Trrmatotrochus 

 Ues in the fact that while it has all the characters and appearance of a 

 Turbinolid, the w^all is penetrated by large perforations between the 

 costffi, giving free communication between the interseptal chambers and 

 the exterior. It thus lessens the validity of the distinction between 

 Perforata and Imperforata. 



S. J. Hickson f makes some notes on Ruth Harrison's paper, especially 

 as regards geographical distribution. The hypothesis of a direct sea- 

 connexion, in the past, between the Atlantic and Indian Oceans is 

 strengthened by the occurrence of Pyi'ophyllia and Ouynia in the 

 Persian Gulf. 



Variability of Fresh-water Medusoid.:]: — C. L. Bouleuger calls atten- 

 tion to the variety of abnormalities in Mmrisia lyonsi from Lake Qurun 

 in the Fayum Province of Egypt. All his specimens were collected in 

 the same locality, and all were males. Eleven out of 400 deviated from 

 the general tetramerous symmetry ; one had only three radial canals, 

 three tentacles, and three gonadial diverticula ; nine had five and one 

 had six of these structures. A second group of abnormal individuals 

 includes a number of tetramerous forms with secondary tentacles between 

 the four primary perradial ones. The secondary tentacles may be inter- 

 radial, adradial or subradial in position, and differ from the perradial 

 ones in not communicating with the gastric cavity by means of radial 

 canals ; they are developed from the ectodermal and endodermal cells of 

 the umbrella margin, their cavities being in communication with the 

 circular canal. Altogether forty-four of the 400 tabulated individuals 

 exhi])ited this kind of abnormality, which is of a very peculiar type. 

 Perhaps the multitentacular forms represent a mutation. Ten had four 

 interradial tentacles as well as the four primary perradials ; twenty-eight 

 had four interradial, eight adradial, and four perradial ; one had these 

 twelve and eight more, two in each quadrant, situated between the 

 interradial and adradial tentacles. 



Axis of Alcyonarians.§ — Hans Neumann has studied the axis of 

 PterogorijiapuuuUa Dana,a species of Gorgonia, Lopliogorgia alba, another 

 species of Lophogorgia, Phxaura Jlavida, and PhxaiireUa dichotoma. He 

 comes to the conclusion, contrary to that of von Koch, that the axis of 



* Proc. Zool. Soc, 1911, pp. 1018-37 (2 pis. and 5 figs). 



t Proc. Zool. Soc, 1911, pp. 1037-44 (1 fig.). 



t Proc. Zool. Soc, 1911, pp. 1045-56 (1 pi. and 7 figs.). 



X Jen. Zeitschr. Naturw., xlvii. (1911) pp. 497-528 (19 figs.). 



