194 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
post-oral segment witli tlie foot-jaws or maxillipedes. It is not 
improbable that the clypeus of Insects and Myriopods may be referable 
to the pre-oral head-lobes of Annelid-like ancestors. 
The posterior maxillae of Chilopoda and Hexapoda are not homolo- 
gous with the most anterior pair of limbs in Diplopoda. The exact 
homologues are wanting in Diplopoda, the corresponding segment being 
more or less rudimentary and without appendages. This is seen clearly 
in Julus and Glomeris , and is probably true for Polydesmus and other 
forms. 
The gnathochilarium of Diplopoda is to be interpreted as a fusion of 
the hypopharynx with a maxillary pair split in two halves. 
S. Arachnida. 
Remarkable Case of Protective Resemblance.* — Dr. E. A. Goelai 
describes a Brazilian species of Cyclosa which illustrates a remarkable 
protective resemblance. On the web there hangs a tube of detritus, 
apparently no random structure ; the spider forms as it were part of 
this tube ; lying horizontally it exactly fills up a gap ; its dorsal and 
lateral markings correspond most deceptively with the irregular mark- 
ings of the particles composing the tube of debris. 
Development of Trombidion holosericeum.f — S. Jourdain describes 
the successive stages : — (1) The embryonic form within the egg-shell ; 
(2) the hatched hexapod parasitic larva ; (3) the sedentary nymph ; and 
(4) the 8-limhed sexual adult. 
Harvest-Mites.f — P. Megnin calls attention to the numerous species 
with red hexapod larvae ( Pougets ), parasitic on insects and mammals — 
dogs, hares, wild rabbits, man, &c. He instances Trombidion Gymno- 
terorum, T. holosericeum, and T. fuliginosum , abundant in various 
localities. 
Hydrachnida of Germany.§ — Dr. R. Piersig has published another 
part of his magnificent monograph on the Hydrachnids of Germany. 
Tardigrada from Spitsbergen. || — Mr. D. J. Scourfield records Macro- 
biotus hufelandii C. Schultze, M. tuberculatus Plate, Echiniscus arctomys 
Ehrbg., and E. spitsbergensis sp. n., from mosses collected during the 
Conway expedition to Spitsbergen in 1896. Two further species were 
also seen, but were not specifically determined. The only previous 
record of a Water-bear (? M. dujardini Doy.) from the island was made 
by Dr. A. von Goes in 1862. 
e, Crustacea. 
Reversal of Respiratory Current in Decapods.^ — Georges Bohn re- 
cently showed that the reversal of the direction of the current of water 
in the branchial chamber, which has long been known in Corystes, also 
occurs in Carcinus msenas, the common shore-crab. Garstang has shown 
* Zool. Jahrb., x. (1897) pp. 563-8 (1 pi.). 
f Comptes Rendus, cxxv. (1897) pp. 965-6. f Tom. cit., p. 967. 
§ Zoologica (Leuckart and Chun), Heft 22 (1897) Lief. 3, pp. 161-240 (8 pis.). 
|| Proc. Zool. Soc., 1897. pp. 790-1 (1 pi.), 
'-If Comptes Rendus, cxxv. (1897) pp. 539-42: and Ann. Nat. Hist., i. 7th series 
(1898) pp. 20-3. 
