126 



79. Daetylopusia thisboides (Glaus). 



(PL LXXVII & LXXVIII, fig. 1). 

 Dactylopus thisboides, Glaus, Die freilebenden Copepoden, p. 127, PL XVI, figs. 24 28. 



Specific Characters. Female. Body moderately slender, conspicuously 

 dilated in front and gradually tapered behind. Cephalic segment rather broad, 

 depressed, evenly arcuate in front, and scarcely longer than the 3 succeeding 

 segments combined ; rostrum of moderate size, obtuse at the tip. Epimeral plates 

 of the 3 succeeding segments comparatively small and rounded at the posterior 

 corners. Urosome exceeding half the length of the anterior division, genital seg- 

 ment of moderate size and considerably broader in front than behind. Caudal rami 

 short and broad, apical setse, however, rather elongated, the innermost but one 

 almost twice as long as the urosome. Anterior antennse rather short and densely 

 setiferous, composed of 8 joints, 4 of which belong to the distal part, the latter 

 about as long as the 3 preceding joints combined. Posterior antennae with the 

 outer ramus well developed, terminal joint about the length of the other 2 com- 

 bined. 1st pair of legs moderately strong, outer ramus scarcely more than half 

 as long as the inner, apical claws only slightly curved and finely spinulose on 

 the concave edge; inner ramus scarcely narrower than the outer, with the apical 

 claws strong and distinctly spinulose, the outer one exceeding half the length of 

 the inner. Last pair of legs with the distal joint not very large, rounded oval in 

 form and more or less exstant, so as to be generally wholly visible in the dorsal 

 view of the animal, marginal setse 6 in number, some of them very slender and 

 elongated; inner expansion of proximal joint very large and broad, foliaceous, 

 extending beyond the tip of the distal joint, and provided inside the inner edge 

 with a regular row of short transverse chitinous stripes. Ovisac large, pyriform. 



Male much smaller than female, and exhibiting the usual sexual differences. 

 Inner ramus of 2nd pair of legs with the distal joint somewhat curved at the tip, 

 which carries 2 rather unequal spines, spine of outer edge very strong and con- 

 spicuously expanded at the base. Last pair of legs much smaller than in female, 

 distal joint short, cordate in form, with only 5 marginal setse, 2 of them spini- 

 form; inner expansion of proximal joint very slight, with 3 subequal marginal 

 spines. 



Body of a golden yellow hue, with a chestnut-coloured transverse band 

 across the anterior part of the genital segment. 



Length of adult female about 1 mm. 



Remark*. This form I regard as the type of the present genus. It is the 

 largest and finest of the Norwegian species, and is moreover easily recognizable 



