404 i\Ir. Lubbock on new species of Entomostraca. 



to be described, they consist each of one three-jointed ramus, 

 possess no hairs, but only a few spines, and altogether resemble 

 the same organs in some species of Pontella. In D. Castor and 

 D. americanus, on the contrary, both legs possess two three- 

 jointed branches, and if not ordinary hairs, at any rate a very 

 near approach to them. 



Further, in D. Buteanus, my other new species, the organs 

 in question much resemble the other legs, and indeed differ 

 only in having a spine, stronger than usual, but varying con- 

 siderably in size, on the inner side of the second segment of the 

 outer branch. This spine is the representative of a much larger 

 one which occupies a corresponding situation in the right leg of 

 the male, but (and this is somewhat remarkable) is not present 

 in the left leg of that sex, although present on both sides in the 

 female. 



It follows from Prof. Dana's description, that his species of 

 Calanopia resemble Pontella in their maxillipeds and first pair of 

 legs, but he does not exj)ressly say so, and in other respects they 

 so closely resemble the species now to be described, that I can- 

 not doubt that they belong to the same group. 



Diaptomus Bateanus, n. s. 



Frons obtusa. Cepbalothorax postice rotundatus, mucronatns. An- 

 tennae anticse corpore paulo breviores, setis brevibus, postica pen- 

 ultima articulum longitudine superante, setis aliis brevioribus. 

 Pes posticus maris dexter uiagnus, digito elongate, inflexo. Pedes 

 postici fccminEe pedibus aliis fere similes. 



The rigid male antenna has a series of minute teeth occupying 

 the anterior side of the fifth, sixth and seventh segments, count- 

 ing from the free end, and the hinge-joint is between the fifth 

 and sixth. 



The maxillipeds resemble those of the species which I have 

 named Diaptomus cluhius. 



The first pair of legs have both branches three-jointed ; the 

 basal segment of the lesser ramus bears one hair, the second 

 two, and the third three on the inner margin and two at the 

 apex. The second segment of the larger branch bears one hair, 

 the inner margin of the terminal segment four, and the apex 

 has a large spine, serrated on the outer side. 



The fifth pair of legs resemble those of C. brachiata, but the 

 long spine on the second segment of the outer branch of the 

 ri"-ht leg is curved, but not bent at a right angle. 



The abdomen is four-jointed, and the caudal lamellae and 

 sette are moderately long, the fourth from the outside being the 

 longest. 



