556 FEESHWATER ENTOMOSTEACA OF N.S.W. ii. COPEPODA^ 



Key to species of Boeckella. 

 A. Basal segment of the left leg of the 5th pair in the male bearing a serrated 

 lamella. 



B. Endopodite of the right leg of 5th pair in male, without an inward 



projection triarticulata. 



BB- Endopodite with an inward projection. 



C Endopodite of the left leg two-segmented. . . fluvialis. 



CC. Endopodite of the left leg one-segmented. 



D. Serrated lamella of the basal segment with a pointed 



projection coronaria. 



DD. No such projection ohlonga. 



AA. Basal segment of the left leg of the 5th pair in th« male without a serrated 

 lamella. 



B. Terminal segment of the exopodite of the 5th pair of legs in the female 



bearing only two spines minuta. 



BB. Terminal segment bearing seven spines. 



C. Endopodite of the right leg of the 5th pair, male, does not 

 reach the end of the second segment of the exopodite and bears 



a curved bristle at the base robusta. 



CC, Endopodite reaches considerably beyond the second segment of 

 the exopodite and has an inward projection at the base. 



pseudocheles. 

 Boeckella triarticulata (Thomson). 



Described by Thomson (1882) as Boeckia triarticulata; first recorded from 

 N.S.W. by Sars in 1896 and from Victoria in 1908 (Plate 1, figs. 1-4). 



Female. Cepbalothorax moderately slender, tapering slightly anteriorly; last 

 segment expanded laterally into two bilobed lappets, the outer lobes of which 

 extend beyond the first segment of the abdomen, the inner lobes are twisted and 

 pointed at the tips. Abdomen about half the length of the cephalothorax; 

 genital segment asymmetrically dilated at the base, being more swollen on the 

 right side than on the left; caudal rami slightly longer than the last segment, 

 widening towards the tips. Antennules comparatively short, extending, when 

 reflexed, to the end of the second segment of the urosome. Fifth pair of legs 

 with the endopodites extending beyond the second segments of the exopodites; 

 the. terminal segments of the latter bearing seven spines. Length, 2.5 mm. 



Male. Smaller than the female. Right antennule geniculated. Fifth pair 

 of legs with the second basal segment of the left leg provided on its inner side 

 with a prominent triangular-shaped lamella, with a serrated edge; endopodite 

 small and simple, reaching about half the length of the first segment of the 

 exopodite. Eight leg with a longer endopodite that almost reaches the end of 

 the second segment of the exopodite and bears a small denticle at the tip; ter- 

 minal claw equal to the length of the exopodite itself, the two other spines of 

 equal size. 



Distribution. — N.S.W. : Rarely found in the neighbourhood of Sydney; Vic- 

 toria; New Zealand. 



BOECiiELLA OBLONGA Sars. 



Sars, Arch. Math, og Naturvid., xxix., 1908, Plate 1, figs. 5-8. 



Female. Cephalothorax narrower than in the preceding species, tapering 

 slightly anteriorly and posteriorly; the lateral expansions of the last segment 

 small, the outer lobes reaching the middle of the first abdominal segment, inner 

 lobes straight and pointed. Genital segment of the abdomen asymmetrical, 

 comparatively longer than in the preceding species and not so much dilated at 



