256 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Ectoparasitic Insects on Mammals.*— Vernon L. Kellogg has pre- 

 viously considered the distribution of bird-infesting Mallophaga, and 

 comes to the conclusion that their host-distribution is governed more by 

 the genetic relationships of the hosts than by their geographical range, 

 or by any other cecological conditions. He has raised the same question 

 in regard to the Mallophaga and Anoplura of Mammals, and has come 

 to the same conclusion. "Considering how few Mammal-infesting 

 parasite species we yet know, it is surprising how repeatedly the com- 

 monness of parasite species to two or more related, although geographi- 

 cally well-separated, host-species, is illustrated." All through the class 

 from Marsupials to Quadrumana, this condition is again and again 

 exemplified. If the conclusion be right, there is an interesting practical 

 corollary, that the distribution of the parasites may give a valuable 

 clue to the genealogical affinities of the hosts. 



8. Arachnida. 



Two New British Water-Mites.t— C. D. Soar describes the males 

 of Arrhenurm scourfieldi sp. n. from Cornwall and Acercus longitarsus 

 sp. n. from South Devonshire. Attention is called to Williamson's 

 records of Sperchon clupeifer Pier, and S. thimemanni Koen., new to 

 the British area. 



*■ Crustacea. 



Optic Tubercles in Stalk-eyed Crustaceans.^— H. Coutiere calls 

 attention to these organs which occur on the stalk of the eye in the 

 Penasid Gennadas and other forms, e.g. Euphausia and Glyphocrangon. 

 In some types they are quite well-developed, in others vestigial. They 

 are most complex in bathypelagic Penrcids, and are doubtless sensory 

 perhaps appreciating some physical character of the water Just 

 as the Nauplius eye may persist in some higher Crustaceans, so the 

 "frontal organs" of some Entomostraca and of larval Euphausids 

 and Pengeids may persist as these optic tubercles ; and an interesting 

 corroboration is afforded by the fact that their nerve, though apparently 

 coming from the optic ganglion, goes right through that structure to 

 the brain. 



New Copepod parasitic on Octopus. § — G. P. Farran describes a 

 new Harpacticid, Gholidya polypi g. et sp. n., from a new situation — the 

 arm-membrane of Polypus eryasticus, from the west coast of Ireland. 

 It is an Idyoid, adapted for parasitic life, with the swimming appendages 

 reduced or absent, and the cephalon and thorax soft and swollen. The 

 cephalic appendages have the same general structure as in the rest of 

 the family ; the inner ramus of the second antenna is very small ; the 



* American Naturalist, xlviii. (1914) pp. 257-79. 



t Journ. Quekett Micr. Club, 1913, pp. 139-42 (2 pis.). 



J Comptes Rendus, clviii. (1914) pp. 886-8. 



§ Ann. Nat. Hist., xiii. (1914) pp. 472-5 (1 pi.). 



