REPORT ON THE COPEPODA. 79 



abdominal somite led me to suppose that the specimen described was a female ; the 

 characters of the anterior antenna and fifth feet, however, are rather those of the male. 



Temora, Baird. 



Calanus (in part), Leach, Diet. Sci. Nat. 



Temora, Baird, Brit. Entomostraca, 1850; Claus, Die frei lebenden Copepoden, 1863; Boeck 



Oversigt Norges Copepoder, 1864 ; Brady, Monog. Brit. Copep., 1878. 

 Diaptonms, Lubbock, Trans. Entom. Soc, 1856. 



Body elongated ; head distinct from the thorax ; rostrum furcate. Fourth and 

 fifth thoracic segments either completely coalescent, or their separation indicated merely 

 by a furrow. Abdomen composed of four or five segments in the male ; of three in the 

 female. Anterior antennas twenty-four- or twenty-five-jointed ; that of the right side 

 in the male geniculated. Mouth-organs as in Calanus. Inner branches of the swimmino- 

 feet usually two-jointed. Fifth pair of feet in both sexes one-branched ; in the male 

 forming prehensile organs. 



The type of this genus is Temora longicaudata (Lubbock) ; a species in which the inner 

 branches of the swimming feet are all two-jointed, except, perhaps, in the case of the first 

 foot, where the division into two joints is often only indistinctly visible. For the most 

 part the two joints are perfectly distinct, even in the first foot, and they are so figured 

 by Dr. Baird. Claus, however, has made it part of his definition of the genus Temora 

 that the inner branch of the first foot is single-jointed, while those of the second, third, 

 and fourth pairs are two-jointed. Though this is correct as to one of the European species 

 (Temora velox), it is not so, as regards the first foot, with Temora longicaudata, and in the 

 case of Temora dubia, now to be described, the discrepancy extends to the second and 

 third feet of the female, where the inner branches are only one-jointed, while, on the 

 other hand, the inner branch of the first foot is bi-articulate. 



From Calanus and Pseudocalanus this genus is readily distinguished by the structure 

 of the fifth pair of feet, and anterior antennas of the male. From Isias and Diaptomus 

 it is separated by differences in all five pairs of feet, though it must be admitted to be 

 doubtful how far these generic distinctions may remain tenable as our knowledge of 

 allied forms increases. 



1. Temora dubia (Lubbock), (PL XXV figs. 1-17). 



Diaptomus dubius, Lubbock, On some Entomostraca collected by Dr. Sutherland in the 

 Atlantic Ocean, Trans. Entom. Soc, vol. iv. N. S., 1856, p. 21, pL ii. figs. 1-7. 



Length, l-13th of an inch (1*95 mm.). Cephalothorax very robust, about halt' as 



broad as long, rounded in front, subtruncate behind, the posterior lateral angles produced 



into long spinous processes (fig. 16). Anterior antennas of the female (fig. 3) about as 



long as the cephalothorax, twenty-four-jointed, the joints not varying greatly in length. 



