122 Mr. J. Lubbock on two new species o/Calanidse. 



Genus Monops. 



Rostrum furcatum. Antenna antica maris dextra geuiculans, tumida. 

 Oculi superiores nuUi. Ocultis inferior unicus. Pes posticus 

 maris dexter crassus prehensilis. 



These characters distinguish Monops from all the other genera 

 in the family, but I shall presently give my reasons for consider- 

 ing this form as a new genus more at length. It is ti'ue that 

 these are the characters of Anomalocera as given by Templeton, 

 but that genus has in reality four superior eyes. 



I have already given the specific charactei', and it is therefore 

 unnecessary to repeat it here. In general appearance this species 

 resembles L. magna more than any other species which I know, 

 for which reason I have given it an analogous trivial name. 



The cephalothorax is 7-jointed ; the posterior segment is very 

 small, the three anterior large and nearly equal to one another, the 

 other three intermediate in size and also equal to one another. The 

 force which has developed the right anterior antenna and the 

 right posterior leg of the male more than the left, has had the 

 same effect on the posterior angles of the cephalothorax ; that 

 on the right side is at least twice as long as the other. In the 

 female they are symmetrical. The spines of the anterior seg- 

 ment do not project outwards, and therefore are not vdsible from 

 above. The rostrum (fig. 7) is very deeply divided, and the 

 two forks are very delicate, symmetrical, and curved towards 

 each other. Each prong is -^q in length, at the base yoVo' ^* 

 the middle g oHo' ^^^ ^^ *^^ ^P^^ ^^^ more than j^^, in diameter. 

 Those of L. magna, on the other hand, are strong and short, 

 being only y^^ in length. (See Ann. and Mag. Ser. 2. vol. x. 

 pi. X. f. 8). 



The anterior antenna of the female and the left one of the 

 male have at the apex a very long hair j^ in length. The cor- 

 responding hair of the penultimate segment is ^~, and of the 

 antepenultimate -^jq (fig. 10). 



The right anterior antenna of the male resembles that of L. 

 magna more than that of the other species ; it swells and con- 

 tracts again, however, more abruptly than in that species. The 

 prehensile spine is much smaller aod not ringed. The plate be- 

 longing to the eighth segment (see the comparison of the right 

 male antennae in this genus) is not free at the base. The teeth 

 are not so sharp. The eighth and ninth segments have coalesced, 

 so that the bail's which belong to the latter appear to be situated 

 on the former. 



The sixth segment bears a very small plate with a few rather 

 large teeth, analogous to the penultimate plate in L. magna. A 

 glance at the figm-e will give a better idea of the general form 

 of the organ than any description could convey. 



