THE AMPHIPODA. 



39 



1901. Euprimno macropus, Vosseler, Amphipoden der Plankton-Expedition, p. 87, pi. 8. fig. 21. 

 1901. Euprimno macropus, Lo Bianco, Mittheil. Stat. Neapel, vol. xv. pp. 422, 447. 



That macropns is a more scholarly form than macropa must he admitted, hut the 

 practice of polishing and improving the names which our scientific ancestors invented 

 has to my mind the same effect as daylight upon Melrose Abhey, where the rays of the 

 sun " gild but to flout the ruins grey." 



BovaUius, referring to the species Primno Latreillei, Menevillei, and antarctica, 

 established in the ' Challenger ' Report, goes on to say, " After a careful examination of the 

 material at my disposal I am convinced that these three new species are at most varieties 

 of the type species, because the chief differences recorded by Stebbing are liable to 

 great variation, purely individual as well as owing to the age of the animals." Vosseler 

 alludes to and apparently accepts this ojiinion, though withotit including the names in 

 the synonymy of the type species. It is, at any rate, a very convenient view to adopt 

 in dealing with the small specimens contained in the present collection with 3 mm. for 

 the upper limit of length. 



A specimen measuring about 1'4 mm. was obtained between 50 fathoms and the surface 

 at Station 25 e, this being obviovisly a very juvenile form. Its want of a mandibular 

 palp is unimportant, since this deficiency is a permanent character in the female. 

 Some observations, however, may be ofi'ered as to the limbs of the perseon. The gnatho- 

 pods have practically the adult form, but the first and second perseopods differ from 

 those of the full-grown animal by having the fifth joint much broader than the 

 sixth, its hind margin ending in a strong apical tooth, while the rest of its armature 

 is limited to a minute spinule. The third perieopods, as shown in the figure (text-fig. 1), 

 have the front margin of the broad fifth joint furnished only with three large teeth, the 



Fig. 1. 



urp.1 



urp.2 



Kk. 2. 



urp.3. 



prp.3. 



intermediate small ones being wholly absent. Both limbs agreed in their armature, 

 a symmetry which Dr. BovaUius found to occur only once in fifteen specimens 

 which he examined of various sizes from 1'5 to 12 mm. in length. The fourth 

 perseopods have the front mai-gin of the fifth joint armed only with an apical tooth. 

 The fifth pair are very small and peculiar. The second joint is straight, narrow, 

 slightly tapering to the distal end. and longer than all the remainder of tlie limb. This 

 consists of a short third joint followed by a blade-like narrowly ovoid but distally pointed 

 piece, which may be taken to represent the last four joints in one. 

 The pleopods at this stage have three-jointed rami. 



