376 CARL BOVALLIUS, AMPHIPODA HYPERIIDEA. I. 2. PHRON1MIDJE. 



Phronima atlantica. 



In 1840 H. Milne Edwards characterized the species with the following words: 



»Pates des deux premieres paires greles et sans elargissement vers lc bout. Deux dents 

 entre le doigt immobile et la base de la griffe des pates de la cinquieme paire.» 



In 1862 Spence Bate recorded Phronima atlantica as follows: 



»Third pair of pereiopoda having two large tubercular teeth on the inferior margin of the 

 carpal or fixed process. » 



In 1882 Streets described male and female specimens, taken in the Pacific. The 

 following passages may be quoted: 



•»Female. — — — — The third and fourth pairs with the basal joint armed behind, at its 

 extremity, with a sharp spine; the basal joint of the fifth pair armed in the same manner as the 

 two preceding, but the spine is much larger in the former; there is likewise a spine on the 

 middle of the following joint, in front. The third joint of the fifth pair enlarged, arched above, 

 and lengthened; the fourth joint, or palm, long, attenuated at its articulation with the third, and 

 gradually broadening to its junction with the fifth joint, arched above, the inferior angle pro- 

 duced anteriorly into a long and stout joint, corresponding to the immovable finger of the Can-- 

 cridce, the anterior border with two stout, prominent teeth, the upper the larger, tuberculated 

 on the edge towards the movable finger, and beset with a few bristles or hairs; the fifth joint, 

 or movable finger, longer than the anterior border of the palm, arched above, and with a broad 

 prominence on the middle of the inferior margin; the last joint very small, and in old subjects 

 fused with the preceding joint. — — — » 



»Mcde. The fifth pair of thoracic legs relatively shorter in the male; all the joints of the 

 leg individually shorter and stouter than the corresponding parts in the female. The produced 

 portion of the fourth joint, corresponding with the immovable finger of a crab, more produced 

 downward, and less anteriorly, and arises from about the middle of the inferior surface. The 

 fifth joint is more curved at its proximal extremity, so as to antagonize with the produced portion 

 of the fourth joint. These sexual characters of the fifth pair of legs are only developed in the 

 mature male; in the young of this sex, the fifth pair partakes of the characters, more or less, of 

 the young female.» 



In 1888 Stebbing gave a description and drawings, to which I refer the reader, 

 here adding some details. 



The f e m a 1 e. 



PI. XVI, fig. 19—26. 



The body is more slender and thin than in Phronima sedentaria. The integument 

 is entirely pellucid, and very thin. 



The first pair of antenna (PI. XVI, fig. 21) are fixed considerably below the middle 

 of the front side of the head. The single peduncular joint is nearly twice as long as 

 broad. The single flagellar joint is thick and tumid at the apex, and is covered with 

 olfactory hairs. The flagellum is nearly three times as long as the whole peduncle. 



The percBon. The first two segments are only a little deeper and somewhat longer 

 than the third segment. The seventh segment is as long as the three preceding to- 

 gether. 



