12 Carl Bovallius, The Oxycephalids. 



II. THE SYSTEMATICAL POSITIOÎ^ OF THE OXCYCEPHALIDS. 



H. Milne Edwards was the first who arranged the Hyperi- 

 idean genera, into subdivisions, establishing in 1840 the following three 

 »tribus». 



1. -»Hypérines gammaroïdesy)^ 2. 'i)Hypérines ordinaires^') and 3. ^Hy- 

 pérines a normales)). The characteristics used by him for distinguishing 

 these subdivisions were: — 



1. The size of the head, »Tête petite» and »Tête très grosse». 



2. The width of the body, »Corps comprimé» and »Corps renflé». 



3. Maxillipeds with palps, — or wanting a palp. 



4. The second pair of antennœ straight, or zigzag-folded, — »Antennes 



de la seconde paire styliformes», and »Antennes de la seconde 



pair se reployant sur elles mêmes, etc.» 

 Of these characteristics the third one, depending on a wrong observa- 

 tion, may be dropped without further discussion; the s«?co?k/ characteristic 

 varies, according to our present knowledge of the Hyperiidean species, 

 so very much, not only among closely allied genera and species, but also 

 in the case of the sexes of the same species, that it has no value what- 

 ever. The first characteristic varies in the case of two so nearly rela- 

 ted families as Vibilidœ and Cyllopodidœ and may thus be assigned the 

 value of a family-characteristic, but not that of a subtribal one. The 

 fourth may be considered as a good characteristic; with regard to the 

 first subtribe, it may be observed however that the form of the second 

 pair of antennae of the first five families in the following synoptical dia- 

 gram show some tendency to the »folding type», so strongly developed 

 in the Oaycephalidœ and their allies. 



J. D. Dana, the next systematizer of the group, placed the Hyperids 

 in three families, 1. Hyj)eridce, 2. Phronimidce., and 3. Typhidce. The 

 principal characteristics were: — 



1. The second pair of antennee extant, — or able to be hidden 

 under the head or the body. 



2- The hind part of the body able to be inflected or doubled up 

 under the body, — or not possessing this faculty. 



3. The fifth and sixth pairs of legs mediocre, simple, — or thick, 

 elongated, often prehensile. 



