ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 465 



Incertse Seuis. 



Animal of Doubtful Affinity.*-- Baldwin Spencer describes as 

 ffologloea dubia a peculiar organism thrown up on the shores of the 

 southern coast of Victoria. It has the form of a mass of stiff jelly with 

 four sides and an oral and aboral end. The mouth lies in the middle 

 of the oral surface, and leads into a flask-shaped cavity. From the 

 central point of its distal end there arises a very small but distinct tube, 

 which runs up to and opens on a conical projection on the aboral 

 surface. The distance between oral and aboral surfaces is 11 mm. 

 Eacli of the four margins is bounded by a very distinct band of finely 

 punctated material. Four of the fourteen specimens showed an "oral 

 organ," a small horse-shoe shaped process, a little like a stolon. It may 

 be that this enigmatical organism is a nurse-form in the life-history of 

 some animal. 



Echinoderma. 



Luminescent Ophiuroids.f — Emanuel Trojan finds that the seat of 

 luminescence in Ophiopsila annulosa and 0. aranea is in glandular cells, 

 that the luminescence is intracellular, and that it occurs under the 

 direct influence of the nervous system. 



Nucleus and Cytoplasm in Sea-urchin Development.! — E. 

 Godlewski, jun., finds evidence during the segmentation-period of a 

 transformation of cytoplasm into nucleoplasm. Increased temperature, 

 salinity, and alkalinity increase the frequency of cell-divisions, and thus 

 influence the absolute quantity of chromatin. The size of the plasmic 

 areas which gather round the individual nuclei is dependent on the size 

 of the nuclei. These are three of the many interesting conclusions 

 reached by the author. 



Echinoderm Larva from Lower Silurian.§ — Anton Fritsch dis- 

 cusses what Barrande called " fnrca bohemica " — a minute flat disk with 

 four processes. The margins bear quadrangular plates as in some star- 

 fishes. On the middle of the smooth disk there is a rounded elevation. 

 Fritsch draws the remarkable conclusion that " the furca was probably 

 the pluteus of a Crinoid." 



Ccelentera. 



Species of Hydra. || — A. Brauer discusses the various species. 

 Besides //. viridis (which Pallas called H. viridissima) there are : 

 (1) H. vulgaris Pall. (= H.grisea L., H. aurantiaca Ehrenberg, H. rubra 

 Lewis, H. tremblegi Haacke, and probably H. attenuate Pallas) ; (2) H. 

 oligactis Pall. (= H. fusca L., H. roeselii Haacke, H. rJisetka Asper, 

 //. monmcia Downing, H. dio&cia Hefferan) ; and (3) H. polypus L. 

 (= H. aurantiaca Korotneff, H. fusca Brauer, Hefferan, and Downing). 

 Definitions of the three species are given. 



* Proc. R. Soc. Victoria, xxi. (1909) pp. 401-9 (2 pis.), 

 t Arch. Mikr. Anat., lxxiii. (1909) pp. 883-912 (1 pi.). 

 X Bull. Internat. Acad. Sci. Cracovie, 1908, pp. 522-6. 

 § Zool. Anzeig., xxxiii. (1909) pp. 797-8 (1 fig.). 

 II Tom. cit., pp. 790-92 (2 figs.). 



Aug. 18th, 1900 2 I 



