REPORT ON THE AMPHIPODA. 1225 



other, the inner margin as it approaches the widened end being set with six or more 

 powerful, strongly projecting spines, graduated in size, the largest at the broad end of 

 the organ, the rounded apical part being set with a fan-like arrangement of slender spines. 

 The fourth perseopods in this specimen were preserved, although, unfortunately, in an 

 imperfect condition ; they have the first joint intermediate in size between that of the 

 third and fifth pairs ; the third joint much longer than in the third peraeopods, rather 

 shorter but broader than in the fifth ; the fourth joint longer than the third and longer 

 than in the fifth pair, with spines at five or six points of the front margin, and smaller 

 spines at seven or eight points of the hind margin ; the fifth joint is nearly as long 

 as the two preceding together, and, therefore, of very great length ; the slender sixth 

 joint was broken; the distal part being broken in each of the last three pairs of perseopods, 

 it can only be stated with the necessary reserve, but still as almost a matter of certainty, 

 that the fifth are longer than the third, and the fourth longer than the fifth. 



Concluding Observation on the Gammarina. 



In 1876 Dr. v. Willemoes Suhm writes with regard to Tristan da Cunha, that they 

 there found " Gammarus everywhere under stones." It is possible that specimens were 

 not thought worth collecting, but at any rate I have not found in the collection of 

 Amphipoda entrusted to me any shore specimens from Tristan da Cunha. 



(ZOOL. CHALL. EXP. — PART LXYII. — 1888.) XxX 154 



