1896. | OF THE GENUS SERGESTES. 949 
Grovr I. 
Mzp.} at most but litile longer, sometimes shorter than trl.’, its first 
joint rarely, the second—fourth joints never obviously incrassated in 
proportion to the joints in trl.*, its two distal joints with numerous 
bristles along both margins. (In the Mastigopus, S. longispinus, 
Bate, the first joint is somewhat incrassated, the fifth joint with 
but few bristles, the sixth only with sete along the one margin.) 
A. On the ext. br. of urp. the ciliated part never occupies the 
half of the exterior margin. 
a. The body very long and slender; the distance between 
the eye-stalks and the mandibles very long. 
S.tenuiremis, Kr., H.J. H. 
S. junceus, Bate. 
S, longicollus, Bate. 
b. The body shorter and less slender ; the distance between 
the eye-stalks and the mandibles not very long. 
a. The first joint in the antenn. ped. about as Jong as or 
shorter than the third. 
*S.atlanticus, M.-Edw. (S. frisii, Kr., 
S. pacificus, Stimps.). 
S. ancylops, Kr. 
S. ovatoculus, Bate. 
*S. cornutus, Kr. 
1 S, longispinus, Bate. 
*S.inows, Faxon.) 
G. The first joint in the antenn. ped. considerably or 
much longer than the third. 
1. The second and third joints in the antenn. ped. stout. 
*S. robustus, Smith. 
*S. japonicus, Bate (S. mollis, Smith). 
*§. bisulcatus, Wood-Mas. (S. phorcus, 
Faxon, olim). 
2. The second and especially the third joint in the 
antenn. ped. slender. (The arcézcws-group.) 
*S. arcticus, Kr. (S. meyert, Metzger, 
S. magnificus, Chun). 
S. rinkii, Kr., vix Bate. 
S. dissimilis, Bate. 
S. mediterraneus, 0. sp. 
*S. prehensilis, Bate. 
*S. kroéyeri, Bate. 
S. dorsospinalis, Bate. 
{ S. laterodentatus, Bate. 
S. nasidentatus, Bate. 
(S. rinkut, Bate, vix Kr.) 
S. leviventralis, Bate. 
*S.rubroguttatus, Wood-Mas. 
1 According to the description this species must belong to this subdivision , 
but it does not agree with the figure (op. cét, pl. li. fig. 2), which shows the first 
joint a little longer than the third, 
