167 



Norway, up to the Troiidhjemsfjord, in depths varying from 20 to GO 

 fathoms. 



Distrihiilkm. — British Isles, Kattegat, Bohuslaii (Stockholm Museum). 



2. Ampelisca tenuicornis, Lilljeborg. 



(PI. 58, (ig. 1). 



Anipeliscii tenuicornis, Lilljehoifi, Oi'veie. af Vet. Akad. Fiiihandl. 1856, p. 123. 



Syn: Ampelisca livvigata, Sp. Bate (not Lilljeborg). 



Cephalon slightlj' exceeding the length of the 3 anterior segments of 

 mesosome combined, frontal part strongly curved anteriorly and ohliciuely 

 truncated at the tip. First pair of coxal plates rather expanded in their 

 iiuter part, with tlie anterior edge strongly curved; -J-tli pair scarcely more 

 dee]) than broad, lower edge ol)li(iue, and longer than the hind margin. Last 

 pair of epimeral plates of metasome rectangular, lateral corners in female 

 sharjjcned, in male more obtuse. First segment of urosome in female but 

 slightly inijiressed at the base dorsally, and having behind the de})ression only 

 a very low and scarcely projecting keel; tliat of male with a deep transverse 

 depression, behind which is a distinct though rounded carina. Corneal lenses 

 about as in the preceding species, underlying pigment of somewhat irregular 

 form, and bright red. Superior antennae in female about the length of the 

 ce])haliin and the first 2 segments of mesosome combined, and reaching a little 

 beyond the middle of the last peduncular joint of the inferior ones, 2nd joint 

 of the peduncle about twice the length of the la.st one, Hagellum nearly twice 

 as long as the peduncle, and composed of about 11 articulations. Inferior 

 antenna; very elongated and slender, nearly attaining the length of the body, 

 dagellum clothed posteriorly with fascicles of slender bristles. Antennae in 

 male about as in the preceding species. Anterior gnathopoda somewhat 

 stronger than in that species, jiropodos having the inferior edge considerably 

 bulging out above the middle. Posteiior gnathopoda slender, with the pro- 

 podos sublinear, and exceeding half the length of the carpus. Dactylus of 

 the anterior pairs of pereiopoda about ei[ualling in length the 2 preceding 

 joints combined. Last pair of pereiopoda with the basal joint scarcely longer 

 than the remaining part of the leg, posterior expansion nearly transversely 

 truncated at the tip, and not reaching beyond the ischial joint, the latter 

 about as in the preceding species, propodal joint, on the other hand, con- 

 siderablj^ larger, exceeding the length of the 2 preceding joints combined, 

 dactjdus comparatively short. Last pair of uropoda with the rami scarcely 

 twice as long as the basal part and having in female a smaller number of 

 marginal bristles than in A. typica. Telsou comparatively narrower than in 



