THE COPEXHAQEX MUSEUJSI AND OTHER SOURCES. 425 



subchelate ; fifth joint distally wide, sixth subquadrate. Pifth perieopods shorter than 

 fourth. Third uropods not elongate ; outer ramus one-jointed, inner minute. Telson 

 partly (or wholly) cleft. 



The type-species is Neoniphargus Thomsonl, a new name for Mr. G. M. Thomson's 

 Niphargus montanus, 1893, from Mount Wellington, in Tasmania. As Costa's Gammarus 

 montanus, 1857, appears to be a Niphargus, the name used by Thomson was pre- 

 occvipied. A second sjiecies, doubtfully assigned to this new genus, is the Gammarus 

 puteanns of Moniez, 1889, from subterranean waters in Prance. It was renamed 

 Nij^hargus Moniezi by Wrzesniowski in 1890. 



Hakonboeckia, n. g. 



Near to AxelboecMa and Gmelinopsis. Segments of peraeon with margins acutely 

 produced. Head with rostral and lateral projections. Antennye with equal peduncles, 

 first pair the longer ; accessory flagellum very small. Hand of first gnathopods lilie that 

 of second, but larger. Third to fifth perseopods with the second joint broad, not pro- 

 duced downward. Third urojiods with subequal rami, the outer ramus (seemingly) one- 

 jointed. Telson cleft nearly to base. 



The generic name is given in compliment to Hakou Boeck, who edited his brother's 

 well-known woi'k on the Aniphipoda of the North. 



The type-species is Hahonhoeckia Strauchii (Dybowsky), 1874, from Lake Baikal. 



Baikalogammaetjs, n. g. 



Near to Gammarus. Pleon-segments, from the second, third, or fourth to the sixth, 

 with a few dorsal setules or spinulos. Pirst tmtennae longer than second, but with a 

 shorter peduncle ; accessory flagellum very short. Hand of first gnathopods not smaller 

 than that of second. In third to fifth pertpo^wds the second joint broad, the wing pro- 

 duced downward in a long rounded lobe. Third lu'opods rather elongate ; the peduncle 

 as long as the two-jointed outer ramus. Telson cleft. 



The generic name alludes to Lake Baikal, so prolific in Gammaridae. 



The type-species is Balkalogammarus pullas (Dybowsky), 1874, from Lake Baikal. 



Gen. Melita Leach, 1814. 



Besides the accepted species of this genus, there may be referred to it with more or less 

 probability Maera conferticola Stimpson, 1857; Ampjhltoe Gayi Nicolet, 1849; and 

 Gammarus tenuicornis Stimpson, 1856. 



Stimpson's Chinese species may or may not be the same as Dana's Melita tenuicornis, 

 1852, from New Zealand. Dana's 31. tenuicornis is a synonym of his own Melita uicequi- 

 sti/lis ; but it will be time enough to consider what should be the designation of 

 Stimpson's species when its distinctness has been proved. 



