368 CARL BOVALLIUS, AMPHIPODA HYPE]iIIDEA. I. 2. PHKONIMIDiE. 



Phronhna sedentaria. 



the middle of the front margin, which is crenulated above as well as below the tu- 

 bercle. The dactylus is present in younger females, and is very short, in the larger 

 specimens it is wanting, and the apex of the metacarpus in there obtusely rounded. The 

 glands are highl)^ developed in this as well as in the other pairs of pera^opoda, for a 

 nearer knowledge of their structure I refer the i^eader to the excellent inemoirs of Claus 

 and P. Mayer. 



The sixth pair reach scarcely to the middle of the carpus of the tifth pair. The 

 fem ur is straight, with feebly convex margins, and is about four times as long as broad; 

 the hjwer front corner is angular and sharp-pointed, and more or less projecting. The 

 ge nu is as long as broad, with the lower front corner projecting and more or less obtuse, 

 in the largest specimens it is broadly truncated. The tibia is narrower than the getm, but 

 is twice as long; the upper front corner is angular. The carpus is linear, longer than 

 the two preceding joints togethcr, and more than half as long as the femur. The meta- 

 carpus is straight, feebly tapering towards the apex, and is quite half as long as the 

 carpus. The dactylus is minute, and sharp-pointed. 



The seventh pair are fully as long as the sixth. The femur is narrow, a little 

 broader above the middle than at the apex; the front margin is nearly straight, the hind 

 margin is feebly convex; the lower front corner projects into a sharp point; the femur 

 is more than five times as long as broad; it is a little longer than the femur in the fifth 

 pair, and a third part longer than that in the sixth. The genu is like that in the pi"eced- 

 ing pair. The tibia is a little longer than the genu, Avith the upper front corner an- 

 gular. The carpus is somewhat longer tlian the two preceding joints together, and 

 scarcely a third part as long as the femur. The metacarpus is more than half as long 

 as the carpus. The dactylus is minute. 



The 2^^^^*^ is almost as long as the whole perteon; the iirst segment is the longest 

 ;uid is nearly as long as the last perajonal segment. The lower hind corner of each 

 segment is produced into a sharp-pointed process, which is longest in the thii^d segment. 



The pleojjoda decrease in size from the Iirst to the third pair. The peduncle is 

 elongate-ovate, and is somewhat compressed. The outer ramus of the first pair has 

 seventeen joints, the inner fifteen. 



The urtls is about as long as the last pleonal segment. The first ural segment is 

 more than twice as long as the last coalesced, which is about as broad as long, with a 

 deep emargination on either side for the insertion of the second pair of uropoda; at the 

 middle of the hind part of the segment there is a broad and deep excavation, in which the 

 telson is fixed, so that the hind margin of the telson projects only a trifle beyond the 

 hind margin of the last coalesced segment. 



The uropoda. The first pair reach to the apex of the thiixl pair. The peduncle 

 is elongated, broader at the apex than at the base, being about seven times as long as 

 it is broad at the base; it is considerably more than twice as long as the inner ramus. 

 The rami are equal in length, elongated and sharp-pointed; the outer ramus is finely 

 serrated along the inner margin and smooth on the outer, the inner ramus is serrated 

 along the outer margin and smooth on the inner. The second pair do not reach to the 

 apex of the peduncle in the last pair, but reach beyond that in the first. The peduncle 



