-558 SUMMAUY OF CUKEBNl' RESEARCHES RELATING TO 



light striking it at an angle of 90° with the major axis, was away from 

 the light. The same pronounced negative reaction followed sudden 

 exposure to light from the front at angles between 90° and 15°. When 

 •exposed suddenly to light coming from the front at angles less than 

 15°, ForceUio moved with less consistency away from the light : but 

 its reactions were, on the whole, markedly negative. This lack of 

 consistencj' was referred partly to the relatively large angular diameter 

 of the source of light, partly to demonstrable inequalities in the sensi- 

 tiveness of the two eves of certain individuals to light. Details of 

 three series of experiments are given in tabular form. 



New Species of Ichthyoxenus.* — Shigemi Ishii describes a parasitic 

 Isopod, Ichthyoxenus opisthopterijuiuni sp. n., found in the abdominal 

 cavity of ten out of sixty-nine specimens of a lish {Acheiloijnathm tabira) 

 from Lake Biwa. Like /. japonensis, the parasite is found enclosed in 

 a membranous sac which lies freely in the body-cavity and opens by 

 an orifice situated close behind the pectoral fin of either side. As the 

 tissue of the sac apparently belongs to the host, and the parasite does 

 not stand in direct contact with the viscera, it is not strictly accurate 

 to say that it is lodged in the visceral cavity. The adults of both sexes 

 and the larvaj are dealt with. 



Viguierella coeca.f — P. A. Chappuis describes this rare Wind 

 Harpacticid, and compares it with Fhylloijnathopas paludosns, which 

 seems to be another species of ViguierelJa. The processes of copulation 

 and oviposition have been observed by Maupas, whose description is 

 published in Chappuis's paper. The early stages of the life-history are 

 described. It seems likely that ViguiereUa is of great phylogenetic age, 

 as is suggested by the number of nauplius-stages, the separate genital 

 apertures, the unpaired copulatory gland whicli represents the second 

 testis, and the presence of a free first thoracic segment with the first pair 

 of legs. There is an interesting pulsating apparatus in the maxillary 

 gland, somewhat like that of Bathynella naians, which is also an antique 

 form. The animal lives in dark mossy crevices, and may be ranked as 

 a " troglophile." It does not need much water. It was, perhaps, in 

 previous times an inhabitant of subterranean waters. 



Fresh-water Entomostraca from Ceylon. $ — Robert Gurney de- 

 scribes Oncocypris pustuJosa sp. n., from Ceylon, which is interesting as 

 regards distribution, for the only other species of the genus is 0. costata 

 Daday, from East Africa. He also deals with Physocypria tuberata sp. n., 

 very near Oypris crenulata Sars, Diaptoimis viduus sp. n., represented l)y 

 a single male among large numbers of D. strigilipes. Many known 

 species are also recorded. 



* Annot. Zool. Japon, ix. (1916) pp. 125-31 (10 figs.). 

 t Rev. Suisse Zool., xxiv. (1916) pp. 521-64 (2 pis.). ' 

 X Proc. Zool. Soc, 1916, pp. 333-43 (3 pis. and 1 fig.). 



