62 BRITISH COPEPODA. 



specific name. The observations made as to the 

 ovisacs and spermatic tubes of Temora velox apply 

 equally to the present species. 



Genus 8. ISIAS, Boeck (1864). 



Body moderately robust, with a well-rounded dor- 

 sum. Abdomen composed in the female of three, in 

 the male of five segments. Anterior antennae 24- 

 jointed, that of the right side in the male forming a 

 geniculated prehensile organ. Posterior antennae as 

 in Calanus. First four pairs of feet with both 

 branches triarticulate. Fifth pair of feet in the female, 

 having the outer branch 3-, the inner 1 -jointed; in the 

 male the outer branch consists of two, the inner of one 

 or two joints. 



1. ISIAS CLAVIPES, Boeck, PI. VII, figs. 313. 



Isias clavipes, Boeck. Oversigt Norges Copepoder, p. 18, (1864). 



Anterior antennae of the female (fig. 4) 2 5 -jointed, 

 about equal in length to the cephalothorax, joints short 

 and broad at the base, and gradually increasing in 

 length to the nineteenth, which is about four times 

 as long as broad ; first fifteen joints of the male 

 antennae each bearing a single club-shaped, ciliated, 

 auditory seta: hinge-joint of the 21-jointed right male 



