366 CARL BOVALLIUS, AMPH1PODA HYPERIIDP1A. 1. 2. PHRONIMID^E. 



Phronima sedentaria. 



The female. 



PI. XVI, fig. 1-3. 



The body is slender; the head and perason together are longer than the pleon and 

 urus together. The integument is pellucid, but tolerably thick. 



The head is bluntly conical, with the upper part the widest and rounded; it is 

 more than twice as deep as long. The front side is fiat, but without antennal groove. 



The eyes have been minutely described by Claus, to whose treatise I refer the 

 reader. 



The first pair of antenncu are fixed below the middle of the front side of the head, 

 and consist of a single-jointed peduncle, which is somewhat longer than broad, and a 

 single flagellar joint. The flagellum is slender, cylindrical, with the apex rounded and 

 set with long olfactory hairs; it is about four times as long as the peduncle, and is com- 

 paratively larger in the young female than in the adult. 



The second pair of antennas are reduced to a tubercular prominence near the lower 

 end of the front side of the head. 



The mouth-organs are exactly like those in Phronima Coletti, and will be described 

 under that species. 



The perwon. The forepart is broad and scarcely compressed, gently narrowing to 

 the hind margin of the sixth segment. The seventh is very long and compressed, equall- 

 ing in length the three preceding segments together. 



The epimerals are entirely fused with the pergonal segments without the slightest 

 trace of a suture in the adult animal, in the young on the other hand the epimerals are 

 indicated as small tubercles above the base of the femora. 



The branchial vesicles are strongly developed at the fourth, fifth and sixth pairs of 

 peneopoda, and attain nearly the length of the corresponding femora. The are attached 

 to the perseonal segments a little behind the insertion of the femora, and are elongate- 

 ovate in form. The vesicles of the second and third pairs are small and thin but distinct 

 in the adult as well as in the young animals. 



The ovitectrices are very thin, laminar, irregularly triangular, and are, when the 

 eggs are deposed in the dwelling of the female, closely pressed against the underside of 

 the peraeon. The are attached to the second, third, fourth and fifth pairs of pera^opoda, 

 inserted close to the bases of the femora. 



The first pair of perwopoda (PI. XVI, fig. 1) reach only a little beyond the lower 

 end of the head. The femur is narrow, feebly curved, and a little longer than the three 

 following joints together. The genu is as long as broad. The tibia is broadly produced 

 at the lower hind corner, and has the under margin truncated and sharply serrated. The 

 carpus is tolerably dilated; the carpal process is gouge-shaped with the front margins 

 convex and sharply serrated; it is quite half as long as the metacarpus. The metacarpus 

 is feebly curved, almost cylindrical, and only a little tapering towards the apex, where it 



