THE AMPHIPODA. l7 



First uropods considerably longer than second; peduncle longer than the rami, which, 

 however, are long and slender, with small spines along both margins and some micro- 

 scopic pectination, the outer ramus the shorter. 



In the second pair the inner ramus is subequal in length to that of the first pair, 

 longer than its peduncle, and much longer than the outer ramus. 



Length, from apex of head to end of fifth pleon-segmeut, 7'5 mm., so that the length 

 to the end of the uropods, but exclusive of the antennae, may be estimated at over 10 mm. 



As the net (the mesoplanktun trawl) was hauled fast, with a view of capturing large 

 organisms, it is not surprising that the specimen was damaged. 



While the generic name refers to the probalile evolution of this genus from Eiisirm, 

 the specific name, meaning "long-wristed," alludes to the character of the fifth joint in 

 both pairs of gnathopods, differentiating this form from all previously known Eusiridae. 



Occurrence: 30 ^, mesoplankton trawl. 2000 to 1000 fathoms. 1 specimen. 



Fam. IscnYROCEUiD^. 



« 



J ASS A, Leach. 



1814. Jassa, Leach, Edinburgh Encyclopsedia, vol. vii. p. 433 (Art. Crustaceology, Appendix). 

 1899. Jassa, Stebbing, Ann. & Mag. Nat. Hist. ser. 7, vol. iii. p. 237. 



3. Jassa pulchella. Leach. » 



1814. Jassa pulchella. Leach, Edinburgh Encyclopaedia, vob vii. p. 433. 



1894. Podocerus falcatus, Sars, Crustacea of Norway, vol. i. pt. 27, p. 594, pi. 212. 



1899. Jassa pulchella, Stebbing, Ann. & Mag. Nat. Hist. ser. 7, vol. iii. p. 239. 



A discussion of the synonymy of this abundant and well-known species will be 

 found in the ' Annals and Magazine of Natural llistory ' above cited, and an excellent 

 description in Sars's great work on the Crustacea of Norway. The celebrated Norwegian 

 author speaks of the " last pair of uropoda with the inner ramus distinctly hooked." 

 According to my observation it is not the inner but the outer ramus that is hooked. 



Occurrences: 24/. fathoms. 3 small specimens. 



21 i. fathoms. 2 specimens and a fragment. 



AMPHIPODA HYPERIIDEA. 



The first three families of this division may conveniently be distinguished by the 

 following synoptic table : — 



(Mandibles with molar ; fingers of fifth pcrjeopods obtuse 3. ViBiLiini:. 



I Mandibles without molar; fingers of fifth periEopods acute. 2. 



^ f Fingers of third, fourth, and fifth perjeopods not retractile 1. Scinid.u. 



"' I Fingers of third, foiutli, and fifth pcrteopods retractile 2. Lanceolm).i;. 



A valuable table for the families of the Hyperiidea at large is supplied by Eovallius in 

 the first part of his monograph on the group, published iji 18S7. 



SECOND SERIES. — ZOOLOGr, VOL. X. 4l 



