Mr. J. Lubbock on two new species 0/ Calanidae. 361 



L. Darwinii, P. Bairdii, A. Patersonii, M. grandis, and L. Pata- 

 goniensis ; and finally, the large annulose appendage of L. magna, 

 in which it attains to its maximum development. If now we 

 count the segments from the apex in A. magna, we shall find that 

 it is apparently situated on the ninth ; two therefore are evidently 

 either soldered together or missing, and at the same time the 

 fourth shows traces of consisting of three ; in M. grandis the 

 apical one of these three is distinct from the other two, and in 

 L. Darwinii there are transverse lines, which divide it into three 

 segments, but are veiy indistinct. We have now therefore re- 

 duced the twelve anterior segments of the prehensile and non- 

 prehensile antennae in the two sexes to the same type, and no 

 doubt the same might be done with the basal portion; here, 

 however, the joints are much more indistinct, and difier vath. 

 age ; I have not therefore thought it worth while to devote to 

 this inquiry the time which would be necessaiy to work it out 

 satisfactorily, but will content myself with a description of the 

 apical portion, especially dwelling on the law which has evidently 

 presided over the arrangement of the hairs. 



The three first or apical segments are always somewhat alike, 

 small and either distinct as in P. Bairdii, or soldered together 

 as in L. magna ; in either case, however, the boundaries are 

 well marked by the hairs. On the first, these are seven in num- 

 ber. The most internal is the largest, and is either simple or 

 wrinkled ; the next is simple or plumose, the third always lan- 

 ceolate, and the rest either simple or plumose. In some cases 

 these hairs are so delicate, that I could not quite convince myself 

 that they agreed with the above description, and in my single 

 specimen of L. magna several had unfortunately been broken off. 

 I know of no case, however, which disagrees with this rule. 



The second segment has in every case three hairs, two internal 

 and one external. One of the two internal is always lanceolate ; 

 the other two either simple or ringed. 



The third bears one internal and one external, either simple or 

 ringed. In L. Patersonii, however, the external is plumose. 



The following segments are provided with hairs on the outer 

 side only : — 



The fourth segment, which in L. Patagoniensis, P. Bairdii, 

 L. magna, and M. grandis, is intimately united with the two fol- 

 lowing, bears a simple hair in A. Patersonii, a wrinkled one in 

 L. Darwinii and P. Bairdii, and two wrinkled and a small spine. 

 This spine I consider, not as homologous with a lanceolate hair, 

 but rather as a rudimentary plate, of the same nature as those 

 which are more developed and provided with teeth in the suc- 

 ceeding segments. 



The fifth bears a lanceolate hair in L. magna, Patagoniensis and 



