296 SUMMARY OF CURRENT RESEARCHES RELATING TO 



sexual dimorphism is slight, the male possessing no ventral plates or 

 shields ; coxa I is never bifid ; trochanter I has a blade-like dorsal 

 retrograde process. Forty-two species are dealt with. They occur on 

 Mammals and birds. Nuttall and L. E. Robinson add a second 

 bibliography (32 pages) of Ixodoidea. 



New Pentastomid.* — Mary L. Hett describes from a N. African 

 snake {Zamenis ravigieri) a new Pentastomid, which, apart from 

 histological differences, is distinguished from a true Porocephalus in the 

 bifid caudal extremity, the anterior mouth opening, the vesicular 

 protuberances round the hooks, the lower degree of development in the 

 male genital system, the unpaired vesicula seminalis lying dorsal to the 

 gut, the correlated dorsal extension of the vasa deferentia and dorsal 

 position of the ejaculatory ducts, the uncoiled uterus in the female, and 

 the anterior position of the female genital aperture with correlated 

 differences of arrangement in the uterus and vagina. 



e. Crustacea. 



Gall-forming Crabs.f — F. A. Potts describes the stages in the forma- 

 tion of the galls by Hapalocarcinus marsiqjialis Stimpson in colonies of 

 Focillopora and Seriatopora. A preliminary paper has been already + 

 referred to. The minute male, described for the first time by the author, 

 is found in open galls with females which have just reached maturity. 

 The females vary in size, from very small individuals with narrow 

 abdomen without appendages, gonads, or genital apertures, to large 

 forms with hypertrophied abdomens forming brood-pouches laden 

 with developing eggs. The galls correspond in development to their 

 inhabitants. 



The peculiarities of the buccal appendages and the reduction of the 

 armature of the gizzard are interpreted on the supposition that the crabs 

 live on the uannoplankton drawn into the galls with the respiratory 

 current. 



In Cryptochirus coralliodytes the male sometimes forms shallow pits, 

 and does not inhabit the same pit as the female. The sexual dimorphism 

 is much less marked than in another species, C dimorphns. The buccal 

 appendages and the gizzard show the same peculiarities as in Hapcdo- 

 carciniis, and a similar feeding is probable. 



First Record of a Species of Palsemonetes in Australia. § — 

 W. J. Dakin describes P. australis sp, n., a prawn-like crustacean 

 extremely common in many of the rivers near Perth, Western Australia. 

 It is also found in shallow lakes on the coastal plain. It probably 

 breeds in the early months of the dry season. This record is a 

 noteworthy increase in the known geographical range of the genus. 



* Quart. Jouni. Micr. Sci., Ixi. (1915) pp. 185-200 (5 figs.). 

 + Papers Dept. Mar. Biol. Carnegie Inst. Washington, viii. (1915) pp. 33-69 

 (3 pis. and 19 figs.). 



t See this Journal, 1914, p. 350. 



§ Proc. Zool. Soc, 1915, pp. 571-4 (1 pL). 



