REPORT ON THE AMPHIPODA. 1409 



uropocla." He gives the length as 15 to 30 mm., and the habitat as Greenland, Spitz- 

 bergen. The telson, though very small, is as long as the breadth at the base, and is 

 therefore nearer to half an oval than to half a circle, alike in Bovallius' figure and in the 

 Challenger specimens. 



Hansen considers that Themisto compressa, Goes, and Themisto bispinosa, Boeck, 

 are the same species, the former grounded on the young, the latter on the adult. In 

 specimens 7 mm. long, he has found, he says, the last three peraeopods of equal length, 

 and though in the third pair the fifth joint was longer than in the two following pairs, 

 the fourth joint was somewhat shorter. In some specimens 8 to 9 mm. long he found 

 the differences between these limbs extremely small, and in larger specimens he found all 

 sorts of gradations in the differences of length. It must, however, be remarked that Goes 

 clearly had the adult before him as well as the young, for he says, " T. compressa n., 

 carinata, segmentum septimum ssepe etiam sextum et octavum margine postico in 

 spinulam productum dorsalem in juvenibus exiguam, in adultis facile conspicuam; antenna? 

 $ flagello multiarticulato, tenuissimo, valcle elongato ut in Hyperiis omnino." In Goes' 

 figure the fifth perseopod is actually longer than the third or fourth. The Challenger 

 specimens are numerous and of many different sizes, from one-quarter to three-quarters of 

 an inch in length, and in the development of the dorsal teeth they vary greatly, but 

 though many were examined especially with a view to this question, none of them in the 

 least agreed with the figure given by Goes of the last three peraeopods of his Themisto 

 compressa; but the small specimens just as well as the large showed a very marked 

 superiority of size in the third peraeopods over the fourth and fifth. I do not, therefore, 

 in the present state of the evidence, feel justified in accepting Professor Hansen's view 

 that Parathemisto compressa (Goes) is the same species as Euthemisto bispinosa 

 (Boeck). 



Length, as above stated, varying from about one-quarter to three-quarters of an inch. 



Localities.— Station 50, May 21, 1873; off Halifax, Nova Scotia; lat. 42° 8' N, 

 long. 63° 39' W.; surface ; surface temperature, 45°. Numerous specimens. 



Station 46, May 6, 1873 ; off Nova Scotia; lat. 40° 17' N., long. 66° 48' W.; surface ; 

 surface temperature, 40°. Two specimens. 



Remarks. — In one of the two specimens from the second locality, there is on one side 

 of the animal a dwindled third perseopod, and the companion limb has perhaps not 

 attained its full size, since the fourth joint is considerably larger than in the following 

 pairs, while the fifth joint is very little larger. 



(ZOOL. CHALL. EXP. PART LXVII. — 1888.) ^XX 177 



