REPORT ON THE AMPHIPODA. 1403 



Genus Hyperiella, Bovallius, 1887. 



18S7. Hyperiella, Bovallius, Systematical List of AmpL Hyper., Bihang till K. Svensk. 



Vetensk. Akad. Hand]., Bd. 11, No. 16, p. 19. 

 1887. „ Bovallius, Arctic and Antarctic Hyperids, Vega-Exped., Bd. iv. p. 565. 



For the definition of this genus, see Note on Bovallius, 1887 (p. 589). In his work 

 on the Arctic and Antarctic Hyperids, Bovallius adds the observation that " this genus is 

 a link betweeu Hyperia and Euthemisto, the form of the body and of the first two pairs 

 of pereiopoda [First and Second Gnathopods] resembles Hyperia, but the elongated fifth 

 pair [Third Perasopods] and the long urus [afterpart of pleon] verge to Eutliemisto." 



Bovallius includes the little Hyperia pupa of Costa, from the Mediterranean, 

 doubtfully in this genus, but the large telson and short small third uropods scarcely 

 reaching beyond the telson make such an inclusion altogether improbable; for a different 

 suggestion, see Note on Costa, 1857 (p. 297). Bovallius includes Dana's Lestrigonus 

 fuscus, from the Mid -Atlantic, in this genus apparently without hesitation, but though 

 Dana describes and figures the third pereeopods as a little longer than the fourth and fifth 

 pairs, he draws the fifth joint as of about the same length in all the three pairs, although 

 in the ascertained species of this genus that joint is strikingly more elongate in the third 

 peraeopods than in the two following pairs. 



Hyperiella dilatata, n. sp. (PI. CLXXL). 



Head deep and broad, not long ; all the peraeon-segments distinct, the peraaon in 

 dorsal view broadly oval, the distal end the narrower ; the pleon abruptly more com- 

 pressed than the perseon, the postero-lateral angles of the first three segments produced 

 in short sharp points. The liver tubes large, the heart narrow. The description is 

 taken from the female. 



The Eyes occupying all the surface of the head with the exception of a small 

 triangular space in front above the upper antennae, and a small postero-dorsal triangle. 



Upper Antennas inserted rather below the centre of the front of the head; the first 

 joint of the peduncle longer than broad, twice as long as the second, which is about 

 twice as long as the third ; the flagellum consisting of one long tapering joint, curving a 

 little outwards, two and a half times as long as the peduncle, the lower half of the inner 

 margin fringed with setules not closely set. 



Lower Antennas more slender than the upper, the flagellum of which they about 

 equal in length ; the terminal (or third free) joint of the peduncle cylindrical, rather 

 longer than either of the preceding joints ; the flagellum of one straight tapering joint, 

 more than once and a half as long as the peduncle, having a few small cilia or 

 microscopic setules on various parts. 



