BIHANG TILL K. SV. VET. AKAD. HANDLINGAR. BAND. 4 N:0 8- H 



condary flagellum. The peduncles make more than two thirds 

 of the whole length of the antennge: its first joint is large, in- 

 flated, almost eggshaped, and more than twice as big as the 

 second joint. It carries on the lower side 10 — 11 long bristles 

 in a row obliquely över the joint, each bristle issuing from a 

 little button-like prominence, the bristes being partly ciliated 

 on one side with the cilia arranged in bundles (Pl. IV, fig. 73), 

 partly ciliated on both sides (Pl. IV, fig. 79). Moreover it 

 carries on the lower side a series of short bristles, thicker 

 at the upper end, close beset with long, fine cilige radiating 

 in all directions. The third in the row of these bristles is 

 the strongest; they are placed each on a biadder-like clear 

 prominence (Pl. IV, fig. 55). The following diminish in size, 

 so that the eight and last does not attain the sixth part of 

 the third. They present exactly the same structure as the 

 auditory bristles, observed in Mysis and Gammarus, and may 

 be held, therefore, to have the same function. 



The second joint is a little more than half as long as the 

 first, much broader at the fore-end, but thicker in the poste- 

 rior one. The lower foremost corner ends with a richly 

 haired tubercle. The hairs are of the same form as the long 

 ones of the first joint (Pl. IV, fig. 73). The upper side car- 

 ries bristles of three difierent forms, the longest and most 

 numerous are ciliated on one side towards the ends, with the 

 cilia grouped in one or two bundles (Pl. III, fig. 38). Between 

 these there are short bristles partly ciliated on two sides at the 

 top (Pl. IV, fig. 74), of the same shape as the long ones, partly 

 almost straight, crossbent at the point, with extremely short 

 cilia; these bristles secrete some glutinous matter and may 

 perhaps perform the functions of organs of smell or taste (Pl. 

 III, fig. 39). 



The third joint is shorter than the half of the preceding 

 one and considerably more slender. At its upper end it car- 

 ries the primary and the secondary flagellum. Along the 

 upper side it has some short hairs, ciliated at the point (Pl. 

 III, fig. 54). 



In the lower foremost angle there are some long bristles 

 of the same shape as those of the preceding joint (Pl. III, 

 fig. 38). To this angle the primary flagellum is fixed. In 

 the feraale it has 6 — 8, in the male 8 — 10 joints, or fewer when 

 not fuU-grown. The first joint is the longest and thickest. 



