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BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Family CENTROFAGIDiE. 
CENTROPAGES Krijyer. 
Female: Head separated from thorax and 4th from 5th thoracic segment; ventral eye sometimes 
protruding from ventral surface of head; abdomen with 3 segments, genital segment asymmetrical, 
Anterior antennm 24-jointed (joints 24 and 25 fused) ; their appendages very complete; bristles naked, 
short and flaccid, with difficulty distinguishable from msthetasks. Posterior antennae similar in struc- 
ture to those of Calamus, outer ramus 7 -jointed, as much as 14 times as long as inner ramus. Also mandi- 
ble and maxilla similar to those of Calamus, bnt in certain of species with fewer appendages. Distal 
bristles of anterior maxillipeds (those of the second basal joint and the innerTamus) hook-shaped, with 
spinose plumes, much thicker and longer than proximal bristles ; lobes rather short. First basal joint of 
posterior maxill ipeds with strongly projecting lobes and long bristles with spinose plumes on two median 
10. Centropages typicus Kroyer ; a , female, dorsal aspect; b, male, dorsal aspect ; c, male, right anterior antenna; 
d, male, right fifth foot ; e, female, fifth foot. 
lobes; outer marginal bristles of the 5-jointed inner ramus well developed and plumose as in Calamus. 
Rami of all 5 pairs of feet 3-jointed (in exceptional cases the inner ramus is 2-jointed). First basal joint 
with an internal marginal bristle in first to fourth pairs of feet, second basal with such a bristle in the 
first pair. First basal of fifth pair without an internal marginal bristle ; number of bristles on rami as 
follows : Outer marginal bristles of outer ramus in first pair, 1, 1, 2, inner marginal bristles 1, 1, 4 ; in the 
second to fourth pairs the outer marginal bristles are 1, 1, 3; the inner 1, 1, 5; iu the fifth pair, outer 
marginal bristles 1, 1, 2; inner, 0, 1, 4; inner ramus with 0, 0, 1 outer, and 1, 2, 5 inner marginal bristles 
in first pair; 0, 0, 2 outer and 1, 2, 6 inner marginal bristles in second and third pairs ; 0, 0, 2 outer, 1, 2, 5 
inner marginal bristles in fourth pair, and 0, 0, 2 outer, 1, 1, 4 inner marginal bristles in fifth pair; the 
internal bristle of second joint of outer ramus in the fifth pair is thorn-like and fused with its joint. 
Male : Sexual peculiarities in structure of abdomen, of right anterior antenna, in fifth pair of feet ; 
to some extent also in fifth thoracic segment and third and fourth pairs of feet. Abdomen consisting 
of 5 segments, usually with a very short anal segment; genital orifice sinistral; right anterior 
antenna a prehensile organ, in which joints nineteenth to twenty-first and usually also twenty-second 
