384 SUMMARY OF CUEEENT RESEARCHES RELATING TO 



in the drippino- mossy forest of the extinct crater, at an altitude of 

 1060 m., and P. laaunae sp. n. from the great, shallow, freshwater lake 

 of central Luzon, known as Bay Lake, and connected with the sea by 

 Pasig River. The two species are closely related, and both are most 

 nearly related to P. sylvicola (Dana) from the bottom of an extinct 

 volcano in Xew Zealand. Search in streams between the two stations 

 has so far failed to produce amphipods. The beach form has short 

 antennas and fully developed pleopods ; the mountain form has long 

 antennas and reduced pleopods and heavier armature. Attention is 

 drawn to the interesting fauna of Bay Lake, which includes the curious 

 water-snake, ChersTjdrus yramdatus Schneider, the blood of which is 

 sometimes used by the fishermen to dye their nets. 



Habitat of Mesnilia martinensis.* — F. Mesnil and M. CauUery in 

 their studies of the Lithothamnion littoral zone have noticed that the 

 semi-parasitic Copepod Mesnilia martinensis Canu lives in the tubes of 

 Polydora fiava, an Annelid which makes a burrow between encrusting 

 calcareous Algge and the rock. The resemblance between Mesnilia and 

 Clausia is emphasized. The two genera form a distinct group, allied 

 to the Hersiliidas. 



Antennules of Gynandromorph daphnias.f — R. De. La Vaulx 

 describes a number of anomalies in the antennules of the members of a 

 culture of D. atkinsoni, with numerous gynandromorphs. It seems that 

 gynandromorphism depends on unfavourable conditions in which there 

 are few eggs at a time, and on some disturbance of the sex-cycle, 

 perhaps some indecisive struggle between gamogenesis and partheno- 

 genesis. A male antennule may be morphologically regarded as a 

 female antennule much elongated, with the sensitive seta in an apical 

 position and with a flagellum. 



Annulata. 



Development of Sperm Duct, Oviduct, and Spermatheca in 

 Tubifex rivulorum.J — J. Bronte Gatenby finds that while the gonads 

 appear very early in this worm, it is not till the animal is nearly half 

 grown that the other parts of the genital organs begin to appear. The 

 funnel of the sperm duct is the first part of the genital ducts to appear. 

 The duct itself next begins to differentiate while the funnel is under- 

 going further development. While the sperm duct is still very 

 incomplete the spermatheca begins to appear in segment ten. Last of 

 all the oviduct is developed. The more highly differentiated structures 

 begin to develop first. The development of the ducts is carefully 

 described, the general results corroborating the modern view that the 

 gonoducts are phylogenetically quite independent of nephridla. 



* Bull. Soc. Zool. France, xl. (1915) pp. 176-8 (3 figs.). 

 + Bull. Soc. Zool. France, xl. (1916) pp. 194-7 (4 figs.). 

 I Quart. Journ. Micr. Sci., Ixi. (1916) pp. 317-36 (1 pi. and 1 fig.). 



