392 CARL BOVALLIUS, AMPHIPODA HYPERIIDEA. I. 2. PHRONIMID^E. 



Phronimella elongata. 



In 1885 Carus gave the following Latin diagnosis, translated from Claus: 



»Corpus gracile; abdomen pedibus 3 natatoriis, 2 saltatoriis munitum; pedes thoracales 

 tenuissimi, debiles, et paris III. et magis IV. fere flagelliformes; pedes paris V. unguiferi, haud 

 chelati.» 



In 1887 I gave the following diagnosis of a variety of Phronimella elongata, 

 under the name Ph. Jiliformis. 



»Second pair of peraeopoda much longer than the first; metacarpal processes longer than 

 half the dactylus. Fourth pair longer than fifth. Femora of sixth and seventh pairs equal in 

 length. Second pair of uropoda well developed.* 1 



In the same year Gilks described as a new species Phronimella hippocephala, which, 

 however, in my opinion, is only a very young male of Ph. elongata. From his descrip- 

 tion the following passages may he quoted: 



»The head somewhat resembles that of a horse in shape, but the resemblance is not nearly 

 so striking as that of the first species (= Phronima bucephala) to the head of a bull. It is not 

 so broad at the top, and no fold surrounds it; so that the appearance of a cephalic shield is not 



produced; its dorsal aspect is covered with a large, widely separated pair of apical eyes. 



The thorax is long, narrow, depressed rather than compressed, the first two dorsally visible seg- 

 ments scarcely separable. The third has the inferior angle of its pleuron produced into a sort 

 of triangular spine, overlapping the second. The fourth and fifth, of nearly equal length, form 

 the widest portion of the body; the sixth longer and narrower than these; and the last, the longest 

 and narrowest of all, is provided behind with a spine on either side of the middle line and has 

 this posterior border considerably everted, so as to admit of hyperextension of the abdomen on 

 the thorax.» 



In 1888 Stebbing gave exhaustive descriptions of several forms or varieties of 

 Phronimella elongata, so that, referring the reader to his work, I shall restrict myself 

 to give here only some details respecting the variety which I previously called Ph. jiliformis. 



The female. 



PI. XVI, fig. 51—57. 



The body is very slender, with extremely elongated and almost filiform appendages. 

 The head and perseon together are quite as long as the pleon and urus together. The 

 integument is very thin and vitreous in appearance. 



The head is not twice as deep as long. 



The eyes are smaller, and consist of fewer elements than in the larger and more 

 robust form of Phronimella elongata. 



The first pair of antenna? (PI. XVI, fig. 53) are fixed at the middle of the front 

 side of the head. The single peduncular joint is cylindrical, and is nearly twice as long 

 as broad. The single flagellar joint is very slender, cylindrical, four times as long as the 

 peduncle, and is furnished with six or eight long, olfactory hairs at the apex. 



The peraion. The seventh segment is very narrow, and is somewhat longer than 

 the two preceding segments together. 



