J92 Searlb, A ddi/ion lo Victorian Fresh-Water Copepoda. \_y^i[^'xxx. 



shape of the fifth thoracic legs of the male. It is the smallest 

 species but one of Boeckella, exceeding B. minuta in length by 

 .15 mm. only. 



In quite a number of specimens of this new species taken 

 recently the females were attacked with a parasitic growth 

 attached to the abdomen, forming a globular mass resembling 

 an enormous egg-sac. This in no way impeded their move- 

 ments, nor did it seem to affect their vitaUty. Specimens so 

 afflicted, as well as normal individuals, are exhibited under 

 the microscope this evening. 



Boeckella asymmetrica, J. Searle, n. sp. 



Specific Characters. — Body of female oblong-ovate in form, 

 broadest at the first thoracic segment and tapering anteriorly. 

 Head as long as the three succeeding segments ; fifth thoracic 

 segment bearing narrow lateral projections, slightly divergent 

 and extending as far as the end of the genital segment. Sub- 

 dorsal projections asymmetrical, that on the left side triangular 

 with the point slightly hooked inwards, while that on the right 

 is much smaller and simply rounded off. Genital segment of 

 abdomen asymmetrical, nearly straight on the left side, 

 i:)ulging at the upper part on the right and protuberant on the 

 ventral side. Caudal furca almost as long as the abdomen. 

 First antenna 25 joints, when reflexed reaching beyond the 

 caudal furca ; second antenna, maxilla, maxillipedes resembling 

 those of most Boeckella. Fifth pair of legs in female of typical 

 shape. Egg-sac with 8 to 12 eggs. 



The male is much smaller than the female. First antenna 

 geniculated on the right side, and bearing many asthetasks ; 

 fifth thoracic segment ending in small triangular projections. 

 The fifth pair of legs in male most resemble those of B. 

 minuta. The left leg has the triangular lamella on the inside 

 of the second basal joint, but it is broader and longer than in 

 B. mimita, and the inner ramus is altogether wanting. The 

 right leg is very similar to that of B. minuta, the spine on the 

 second joint being twice as long as that on the first, and the 

 greatly curved apical claw being longer than the ramus itself ; 

 the inner ramus sub-cylindrical, and differing very slightly from 

 B. minuta. 



Length of male, .75 mm. ; of female, 1.45 mm. 



Occurrence. — In most of the pools in the Yarra valley, near 

 Melbourne. 



Explanation of Plate. 



Fig. I. — Boeckella asymmetrica, female, x 60 (about). 



Fig. 2. — Fourth and fifth thoracic segments and abdomen of female from 



right side. 

 Fig. 3. — B. asymmetrica, male, x 60 (about). 

 Fig. 4. — Fifth thoracic feet of male. 



