48 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Norneria gig'as.* — HerrF. Nordenskiold describes this Hydrachnid, 

 and compares it with Linopodes and Penthaleus. It seems to be inter- 

 mediate between the lower Acarids and the higher Prostigmata. The 

 high development of the digestive organs, the complex structure of the 

 oral glands, the nature of the mouth-appendages, the marked differen- 

 tiation of the muscular and tracheal systems, relate it to the higher 

 forms, while in other features, e.g. the character of the mandibles, it 

 resembles the lower acarids. The skin seems to have no glands. As in 

 TrombididaB and Bdellidse, there is no hind-gut. The nervous system 

 approximates to that of Bdella ; there are no eyes, though they have 

 been reported to be present, but there are two peculiar refractive chiti- 

 nous corpuscles on the anterior part of the dorsal surface. A peculiar 

 appendage projects from the pseudocapitulum between the basal joints 

 of the mandibles, and may be comparable to the sensory structure de- 

 scribed by Henking and Schaub between the eyes. The female has 

 an oviposilor, and the eggs are like those of Hydrachnids. 



Atax taverneri. j — Mr. C. D. Soar describes this new free-swimming 

 species collected by Mr. H. Taverner in Highams Park. It appears to 

 be different from any of the 34 or so recorded species, but comes nearest 

 A. aculeatus. 



Classification of Ticks.! — Dr. F. Supino makes a communication 

 of systematic interest on the Ixodidas. There are seven well-defined 

 genera : — Ixodes, Hyalomma, Rhipicephalus, Dermacentor, Hsemaphysalis, 

 Herpetobia, and Opisthodon. He also discusses the characters on which 

 most reliance may be placed in distinguishing species, and briefly 

 describes a number of forms. 



Thelyphonid from Africa.§ — Dr. Ernst Hentschel records an inter- 

 esting find in the Strasburg collection of Pedipalpi. In two different 

 collections he has found specimens of a Thelyphonid belonging to the 

 genus Hypoctonus. The interest of the find is that Thelyphonids have 

 hitherto been described as confined to the Oriental and Neotropical 

 regions, thus affording an example of discontinuous distribution. The 

 collections in which the specimens occurred are respectively marked 

 Senegal and Algeria, but all four forms belong to the same species, and 

 all are females. The genus to which they belong; is Oriental, and the 

 species, Hypoctonus africanus sp. n. $, is intermediate in characters 

 between the Burmese species and M. gastrostictus Kraep. from Borneo. 



e. Crustacea. 



Story of Artemia retold. — In 1875, W. Schmankewitsch published 

 in the Zeitschrift fur wissenschaftliche Zoologie a famous paper, giving 

 an account of his observations on the brine-shrimp, Artemia salina, from 

 the Bay of Odessa. He stated that by altering tlie salinity of the water 

 he could transform A. salina into another species A. muhlhausenii, and, 

 more than this, that by addition of fresh-water to the habitat in which 

 A. salina lived, he could induce a resemblance to the genus Branchipus 



* Acta Soc. Sci. Fennica, xxvi. (1899) 23 pp. and 1 pi. See Zool. Centralbl., vi. 

 (1899) pp. 795-7. t Journ. Quekett Micr. Club, vii. (1899) pp. 219-21 (1 pi.). 

 % Atti Soc. Veneto-Trentina Sci. Nat. Padova, iii. (1899) pp. 241-52 (2 pis.). 

 § Zool. Anzeig., xxii. (1899) pp. 429-31. 



