NO. 5.] ACCOUNT OF THE SPECIES. ' 63 



and the 11th and 12th being coalesced. The sensory appendages are more 

 fully developed than in the female, and are more numerous, especially in 

 the proximal part of the antenna. 



The oral parts, as is not unfi'equently the case in male Calanoids, are 

 imperfectly developed and rather unlike those in the female. Even the posterior 

 maxillipeds (fig. 3) look rather different, and more resemble those in the next 

 genus (Chiridius). 



The last pair of legs (fig. 9) are quite enormously developed, considerably 

 exceeding in length even the whole tail, and, as usual, are rather asymmetrical, 

 though both legs are found to be biramous. The 1st basal joints of the 2 

 legs are united, and together form a rather irregular piece considerably more 

 expanded on the left than on the right side. The 2nd basal joint on both legs 

 is very tumid, but is conspicuously larger on the left than on the right leg. 

 On the other hand, the rami in the latter are longer than in the former. 

 The outer ramus of the right leg, as in the genus Undinella, consists of 2 

 highly chitinized pieces, movably articulated to each other. The proximal piece 

 in this form also is somewhat bow-shaped and considerably longer than the 

 distal one, which projects inside to a rounded lobe. The outer ramus of the 

 left leg is composed of 3 distinct joints, the 1st of which is about the length 

 of the other 2 combined. The last joint is longer than the 2nd, to which it 

 is very movably articulated, and it is slightly bilobular at the tip. The inner 

 ramus is uniarticulate on both legs, and essentially of the same appearance, 

 though that of the right leg is longer and more slender. In both legs, this 

 ramus terminates in a slightly curved lamellar expansion. 



Occurrence. Of this large and conspicuous Calanoid, only 2 specimens, 

 a female and a male, were found, both, however, being in a very perfect 

 state of preservation, and therefore admitting of a rather minute examination. 

 They both occurred in a sample taken between March 23rd and April 4th, 1895, 

 near the 84th degree of latitude, the tow-net having been lowered to 130 metres. 



Gen. Chiridius, Giesbrecht. 

 Remarks. This genus was established by Dr. Giesbrecht in the year 1892, 

 to include a solitary species from the Gulf of Naples, C. Poppei, the chief char- 

 acter distinguishing it from JJndeuchceta being the absence of a rostral pro- 

 jection, the spiniformly produced lateral corners of the last pedigerous segment, 



