1302 THE VOYAGE OF H.M.S. CHALLENGER. 



" Head anteriorly concavated, the upper part more or less projecting into a rostrum. 

 Eyes small, like those in the Gammarids, placed uncommonly far down on the sides of the 

 head. First pair of antennae long, the flagellum more or less lanceolate, tumid ; some- 

 what like that in the Vibilidse. Second pair are long, filiform, with very long joints. 

 Urus [segments in connection with the uropods and telson] like that of the Hyperiidse." 



In 1885 Bovallius mentions that among his new species of Lanceola he has "two 

 totally blind ones," in which case the generic character ought to speak of " eyes small or 

 wanting " ; that the lower antennas are not always filiform has been already observed. 



In this genus the ganglionic chain has its two halves clearly distinguishable, the 

 longitudinal commissures being actually separate, in contrast to the genus Vibilia in 

 which they are closely united. The muscles do not form thick and compact groups, but 

 slender bundles of which the components are easily separable, and in the large segments 

 of the peraeon, instead of a single longitudinal group on either side of the back, there are 

 several slender strips of muscle very distinctly separated. 



Lanceola pacifica, n. sp. (Pis. CLL, CLIL). 



Rostrum small, obtuse, a little depressed ; back of the perseon rounded, its third 

 segment the longest, the second and fourth nearly equal to the third ; the pleon-segments 

 slightly carinate dorsally, the first three also laterally ridged, having the lower part of 

 the hind margin fringed with spinules and sloping forwards to form an obtuse angle with 

 the lower margin, which is likewise bordered with spinules. 



Eyes small but prominent, tending to oval, placed obliquely between the upper and 

 lower antennae. 



Upper Antennas reaching nearly to the middle of the fourth joint of the lower 

 antennae ; the peduncle short and stout, the first joint not so long as broad, as 

 long as the two following together ; the flagellum three times as long as the peduncle, 

 the bulky first joint channelled on one side, and on the other fringed with a brush of short 

 setas or filaments in many transverse rows ; the apex is obliquely truncate and is followed 

 by a very short laminar second joint, with one edge folded, to which succeed two minute 

 terminal joints, much less broadly winged. 



Lower Antennae. — First joint obscure ; second joint short, with a small gland-cone ; 

 third joint twice as long as broad, very setiferous ; the fourth joint two and a half times 

 as long as the third, as long as the whole upper antennas but not quite so broad, 

 triangular in transverse section ; fifth joint as long as the third and fourth together, 

 narrower, tapering to a point, of triangular section till near the apex. It is possible that 

 the fourth joint may represent the fourth and fifth joints of the peduncle coalesced, and 

 that the whole of the tapering fifth joint may be the flagellum ; that its apical part belongs 

 to the flagellum can not be doubted. 



