26 Mr. J. Lubbock on a new genus 0/ Calanidte. 



serrated plate. Eyes two, large, distant. Cephalothoi'ax 7- 

 jointed. External maxillipeds large, bearing long setose hairs. 

 Right male thoracic leg, of the fifth pair, swollen, prehensile. 



I have after much hesitation described this as a new genus, 

 on account of the number and position of the eyes, and of the 

 very remarkable structure of the ninth and tenth joints of the 

 i-ight male antenna. 



From Calanus, Dana ; Scribella, Dana ; Acartia, Dana ; Eu- 

 chceta, Dana, and Undina, Dana, it diflFers in having the right 

 male antenna prehensile. 



From Calanus, Scribella, Euchceta, Undina, Caudace, Dana ; 

 Cyclopsina, Dana, and Catopia, Dana, in having two large distant 

 eyes. 



From Acartia, in having the right fifth leg in the male pre- 

 hensile, and two instead of four eyes. 



From Pontella, Dana, in having two large distant eyes instead 

 of three. 



From Cetochilus, M.-Ed., in having the right fifth leg in the 

 male prehensile. 



From Anomalocera, Tem., in having two eyes in both sexes. 



And from all these genera in the structure of the supei-ior 

 right male antenna. 



Cephalothorax : 7-jointed ; the first three large and nearly 

 equal, the next four gradually diminished in size. 



Eyes : large, distant, one on each side of the head ; alike in 

 both sexes. 



Between the two anterior antennje is a rounded projection 

 analogous to that which in the neighbouring genera contains 

 the inferior eye ; in Labidocera, however, the eye itself is absent, 

 at least Mr. Darwin, who examined the mouth when they were 

 fresh, did not observe it, and had it been coloured like the other 

 two he could not have overlooked it ; and besides, though I could 

 easily dissect out the lenses of the superior eyes, I could not find 

 one here*. 



Anterior antennce : female and left male simple, 24-jointed, 

 like those of Pontella, &c. 



The right male antenna consists of 13 joints. The 1st, 2nd, 

 and 3rd joints, counting from the apex, are simple, long and 

 narrow; the first terminated by a few short hairs, the second 

 and third bearing each a long hair at the apex. The fourth 

 long, narrow, and produced forward into a dentated plate ; 

 closely applied to, and rather longer than, the joint itself. The 



* The colouring matter of the eyes of Entomostracans must differ che- 

 mically fi'om that of the Zoeee, Gammari, &c., for in Mr. Darwin's speci- 

 mens (which have been in spirits of wiuc nearly twenty years) the colour in 

 the former was entirely destroyed, while that of the latter was tnialtend. 



