188 SUMMARY OF CURRENT RESEARCHES RELATING TO 



he Las named after the Curator of the Eoyal Microscopical Society. 

 The principal distinctive feature is that the short and slightly curved 

 lorica is deeply serrated in front, having nine large teeth on the anterior 

 edge, and two unequal and hut slightly curved toes. The size of the 

 body is 95 /a. A further description with figure is promised in the next 

 volume of the Ploner Forschungsberichte. 



Chas. F. Eousselet* describes Triarihra brachiata sp. n., a very small 

 species allied to T. brevispina, but with larger skipping spines, which 

 are quite broad and arm-like at their base. A good figure accompanies 

 the description. The author adds some general remarks on the pro- 

 tective use of spines in Triarihra. 



Ccelentera. 



An Interesting" Medusoid.f — A. Linko describes, from a collection 

 off the Murman Coast, an interesting Medusoid which seemed to be 

 nearly allied to Sarsia br achy g aster Gronberg, but differed from it in 

 the absence of ocelli and in the form of the manubrium. Sections 

 showed that the manubrium bore four endodermic inter-radial longi- 

 tudinal folds from the stomach to near the mouth. These folds suggested 

 the taeniolae of Acalephas, but they seemed to be wholly digestive, for 

 the gonads were located in the ectoderm. 



Occurrence of Cladonema in the Bahamas.:}: — H. F. Perkins records 

 the finding of a representative of this genus, hitherto only known from 

 Northern Europe, in Nassau Harbour, where it was taken in the tow-net. 

 The distinctions from the European G. radiatum seem in themselves 

 sufficient to warrant the erection of a new species, but this view is 

 rendered more doubtful by the fact that the European form is known to 

 be exceedingly variable, and meantime the author reserves judgment on 

 the point. The living medusa possessed the power of attaching itself 

 by means of its tentacles, and then, in spite of its minute size, required 

 some force before it could be dislodged. A fully illustrated account of 

 the structure is given. 



Development of Cordylophora lacustris.§ — Paul Morgenstern sums 

 up his investigations on this subject as follows : — The female sex-cells 

 have an ectodermal origin, and arise in the embryonic zone of the stalk 

 of the chief hydranth. Even at an early stage a distinction into egg- 

 cells and nutritive-cells is obvious, and this becomes more marked in 

 the gonophore where the eggs ripen. After maturation is accomplished 

 by the extrusion of two polar bodies, the ectoderm and endoderm of the 

 gonophore undergo degeneration, and then fertilisation takes place. The 

 formation of polar bodies, fertilisation, and the formation of the first 

 segmentation spindle, all occur at the same pole. Segmentation is ap- 

 proximately regular, and results in the formation of a large segmentation 

 cavity. The formation of endoderm results from the tangential division 

 of the blastomeres, and is multipolar. But the solid cell-mass which 

 arises in this way is not to be regarded as the result of segmentation ; 



* Journ. Quek. Micr. Club, viii. (1901) pp. 143-5 (1 pi.). 

 t'Zool. Anzeig., xxv. (1902) pp. 162-4 (2 figs.). 

 J Johns Hopkins Univ. Circ, xxi. (1902) pp. 25-7 (1 pi.). 

 § Zeitschr. wiss. Zool., lxx. (1901) pp. 567-91 (2 pis.). 



