DR. H. J. HANSEN ON BATHYNOMUS GIGANTEUS. 23 



as the second ; furthermore, the two laciniae considered by me 

 to belong to the same third joint are developed in a similar 

 way in Mysis, which besides possesses a palpus, consisting of a 

 fourth and a fifth joint, not existing in the Isopoda. The 

 presence of both this palpus, of the two narrow^ lobes mentioned, 

 and of the exopod in Mysis, proves that the outer one of the 

 narrow laciniae in-Bathynomus — and other Isopods — cannot, with 

 Bouvier, be regarded as the exopod. A study of the consti- 

 tuting elements of the maxillse in Cumacea, in larval stages of 

 Peneidse, &c., will give the same results (corap. my preliminary 

 morphological paper in ' Zool. Anzeiger,' 1893). 



Maxillipeds. — 1 have nothing to add to the detailed and careful 

 description of Bouvier. But in reference to the free "joint" 

 projecting from the upper side of the second joint at its distal end, 

 he says (p. 151) that " M. Hansen regarde [cet article] comme 

 une lacinie uiais que nous tenons plutot pour un expedite (e^), 

 dont la base d'attache se serait rapprochee de la ligne mediane, 

 en passant par dessus I'endopodite." That the joint in question is 

 a lobe separated by an articulation from the second joint of the 

 maxilliped is proved by comparison with other Malacostraca. 

 In Bathynomus, Cirolana, and Chiridotliea {Glyptonotus') the 

 "joint" is marked off by an articulation ; in Eurycope yigantea 

 (' Dijmphna-Togtet . . . ' tab. 20. fig. "^ g) it is much larger, but 

 not at all marked off at the base, proviog itself to be a lobe from 

 the second joint of the maxilliped, and it is developed in a 

 similar way in many other Isopoda (comp. Gr. O. Sars, ' Crus- 

 tacea of Norway — Isopoda'). Inmost Ampliipo da Gammaridea, 

 for instance in Socarnes (' Dijmphna-Togtet . . . ' tab. 21. 

 fig. 5 h), the same lobe from the second joint has been developed 

 on the same place and marked oif by an articulation, but, besides, 

 a lobe (in Socarnes much larger than the preceding one), not 

 defined by an articulation, has been developed from the third 

 joint. In Mysis the lobe from the end of the second joint is 

 ]-ather short but yet plainly seen, and besides a large exopod 

 projects from the outer side of the same joint near its base. 

 Therefore I must maintain my earlier interpretation, which, for 

 the rest, is not original, being set forth by other authors before 

 the publication of the Crustacea in ' Dijmphna-Togtets zool.-bot. 

 Udbytte.' 



Abdomen. — The French author writes on p. 172 : — " lis nous 

 semble que la piece caudale, avec sa forme semi-circulaire et ses 



