NO. 5.] ACCOUNT OF THE SPECIES. 77 



a 5th of their length beyond the caudal rami. They are composed, as in 

 the 2 above-described species of Pseudocalanus, of 23 articulations, the 7th 

 of which is rather elongated. 



The posterior antennae (fig. 4) have the outer ramus longer than the 

 inner, both being of exactly same structure as in Pseudocalanus. 



The anterior lip (see fig. 3) is rather prominent, and densely hairy 

 at the end. 



The mandibles (fig. 5) resemble those in Pseudocalanus, but have the 

 basal part of the palp less produced at the inner corner, for which reason 

 the inner ramus does not project beyond the outer. 



The maxillae (fig. 6) do not exhibit any peculiarity in their structure. 



The anterior maxillipeds (see fig. 7) are well developed, and, on the whole, 

 built upon the same type as in Pseudocalanus, with the digitiform lobes 

 well separated, and clothed with coarsely ciliated setae, the apical setae being 

 likewise rather strong, though somewhat shorter. 



The posterior maxillipeds (ibid.) are more than 3 times as long as the 

 anterior, and have the terminal part unusually prolonged, being almost twice the 

 length of the 2nd basal joint. Of the 5 articulations composing this part, the 

 2nd is much the largest, equalling in length the 2 succeeding ones combined. 

 The setae of this part are all coarsely ciliated, and some of the outer ones 

 are of veiy considerable length. The perfect agreement in structure of these 

 limbs with those in the type species is very obvious on comparing the figure 

 here given with that reproduced in Dr. Giesbrecht's great work. 



The natatory legs (figs. 8 11) are very slender, and in structure resemble 

 those in the genus Pseudocalanus, except that the inner ramus of the 3 

 posterior pairs is clothed on the posterior face with oblique rows of small 

 spinules. In the type species the outer ramus also has similar spinules. Of 

 the last (5th) pair of legs, no trace is to be detected. 



The adult male (fig. 13), of which only 2 or 3 specimens were found, 

 looks rather different from the female, and strongly recalls the male of 

 Pseudocalanus. It is somewhat smaller than the female, scarcely exceding 

 1 mm. in length, and has the anterior division of the body comparatively 

 broader and more ovoid in form, with the anterior extremity triangularly 

 produced and slightly keeled dorsally. The muscles moving the antennae and 



