70 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Zealand Species of Elasmopus.* — Charles Chilton discusses 

 the Xew Zealand species of this genus of Amphipoda Garamaridea, viz. 

 E. siihcarinatus Haswell, E. )ief/Jectus sp. u., and E. boUonsi sp. n. The 

 genus appears to be closely allied to Maera, and M. viridis HaswelU 

 which Stebbing placed under Elasmopus, is best left under Maera. 

 The species E. subcarinatus and those allied to it appear to be dis- 

 tinguishable from Maera by the small accessory flagellum, by the 

 robustness of the pereeopods, and by the third uropod not reaching far 

 beyond the others. 



Variability of Oral Appendages of Terrestrial Isopods.f — W. E. 

 CoUinge has enquired into the range of variation in the oral appendages 

 of Ligia oceanka, Trichoniscu.'^ roseii.t, Oniscm aselhis, ForcelUo scaber^ 

 P. laevis, Porcellioniiles pruiuosns, and ArmadiUidium vuhjare, and 

 has examined 438 specimens. Of these no fewer than 110 exhibited 

 variations. Thirty-one variations occurred in the form of the mandibles, 

 twenty-eight in that of the first maxilliB, twenty-one in that of the 

 second maxilla3, and thirty in the form of the maxillipedes. The 

 oral appendages are evidently subject to a considenible amount of 

 variation, and for purposes of specific distinction are not of the value 

 generally supposed, and are certainly not so constant as the form of the 

 head, the mesosomatic segments, the antennae, the telson, the uropods, 

 and the thoracic appendages. 



Number of Chromosomes in Male Daphnia.| — Monica Taylor has 

 enquired into the immber of chromosomes in different tissues of the 

 male Daphnia pidex, and also in the various generations of cells in the 

 testis. The number of chromosomes in the spermatogonial cells is 

 the same as in the tissue-cells of the female, and lies between eight and 

 ten. In somatic mitosis the diploid number (eight or ten) is also to 

 be seen. 



Spermatogenesis in D. pidex is perfectly typical. The spermato- 

 gonial cells contain the diploid number of chromosomes ; reduction 

 ensues ; two meiotic divisions follow; the first and second spermatocytes 

 contain the haploid number (some have five, others four). The eggs 

 which develop into males must contain the diploid number of chromo- 

 somes, in which respect they resemble those summer eggs which ha\'e 

 developed parthenogenetically into females. 



Incertee Sedis. 



Polyzoa of 'Siboga' Expedition. §—S. F. Harmer gives an account 

 of the Eutoprocta {Loxocali/x, Loxoso7na, Pedicellina, and Barentsia), 

 and of the Ectoproctous sub-order Ctenostomata and Cyclostomata. 

 Some have thought that Polyzoa do not flourish in tropical conditions, 

 but it is plain that in Malay waters, at least, they are present in large 



* Trans. New Zealand Inst., xlvii. (1915) pp. 320-30 (12 figs.). 



+ Journ. Linn. Soc. (Zool.) xxxii. (1914) pp. 287-93 (2 pis.). 



t Zool. Anzeig., xlv. (1914) pp. 21-4. (Privatel)- reprinted.) 



§ ' Siboga ' Expeditie, Jlonographie xxviii.d (1915) pp. 1-180 (12 pis.). 



