4.38 SUMMARY OF CUERENT RESEARCHES RELATING TO 



Tetranychus moles tissimus of the Argentine Eepublic, a species allied 

 to, if not similar with which appears to be the cause of the Port- 

 natal-sicbt, and possibly of the erythema autumnale which obtains in 

 South France ; on Halarachne halichoeri which has, notwithstanding 

 Kramer's failure to detect it, an eight-footed nymph-stage ; and on 

 Halacarus gossei, a new species which is parasitic on worms and 

 Synascidians ; it is a true Hydrachnid, though it has ordinarily been 

 regarded as an Oribatid ; it resembles the HydrachnidaB in the form of 

 its gnathites ; what earlier authors, e. g. Grube, took for the stigma 

 is really the eye. Dr. Haller remarks that he has recently had an 

 opportunity of examining Pontarachna punctum, and that it is very 

 closely allied to Mygrohates longipalpis. 



Acari of the Genus Glyciphagus.* — Mr. A. D. Michael, during 

 some investigations on mole's nests, discovered two new species of 

 Glyciphagus among the dried grass, &c., forming the nest ; they were 

 not found on the animal itself, nor in disused nests. The genus was 

 founded for certain Acari which feed on fruits, and the author refers 

 to the work by Famouse and Eobin,| wherein the genus is defined ; and 

 he draws attention to the various points of difference exhibited by the 

 males and females of the two new species, G. platygaster and G. dispar. 

 In the former the difference between the two sexes is not more 

 marked than is usual in the genus ; but in G. dispar the difference is 

 almost specific in degree, and had it not been that the author was 

 able to find them in the act of copulation, he would have considered 

 the two sexes as specifically distinct ; the male is deprived of the 

 long hairs and spines characteristic of the genus, and is proportion- 

 ately much broader than the female. The author obtained proof, 

 from the same observations, that the supra-anal papilla in the female, 

 is, as he had surmised, the bursa copulatrix. The characters of the 

 male, female, and nymph of the two species are then given in 

 detail. 



6. Crustacea. 



Abyssal Decapod Crustacea of the North Atlantic. | — Mr. S. I. 



Smith reports on the deep-sea Decapoda collected by the ' Albatross.' 

 Altogether 130 species were taken, but only 44 were found at 

 depths below 1000 fathoms. The first question which arises is, which 

 of them actually inhabited the bottom ; fifteen of them — that is the 

 two Brachyura, the seven Anomura, the Eryontids, Crangonids, and 

 Glyphocrangonidse among the Macrura are unquestionably inhabitants 

 of the bottom ; it is doubtful whether those that are here grouped 

 together as Miersiidee are deep-dwellers, they are among the most 

 common characteristic forms taken in trawling at great depths, while 

 the structure, e. g. the highly developed black eyes, the comparatively 

 small eggs, and the firm integument of Acanthepliyra agassizii and 

 A. eximia, are some evidence that they do not normally inhabit the 



* Journ. Liim. Soc. Lond., xix. (1886) pp. 2G2-82. 

 t Journ. Anat. et Physiol. (Robin), iv. (1867) p. 568 (2 pis.). 

 X Ann. and Mag. Nat. Hist., xvii. (1886) pp. 187-99; abstracted from 

 'Report on the Deunpod Crustacea, of the Albatross,' and published in advance. 



