113 



72. Parathalestris hibernica (Brady & Rob.). 



(PI. LXVIII). 



Thalcstris hibernica, Brady Kobertson, in Ann. & Mag. Nat. Hist., ser. 4, Vol. XII. p. 135, 



PI. VIII, figs. 1719. 



Specific Characters. Female. Body conspicuously compressed and very 

 slender and elongated, with the integuments rather thin and pellucid. Cephalic 

 segment scarcely exceeding in length the 4 succeeding segments combined, epimeral 

 parts much curved in the middle, rostrum of moderate size. Urosome about 

 half the length of the anterior division and having the segments quite smooth. 

 Caudal rami short quadrangular, with the outermost of the apical setae consider- 

 ably thickened at the base. Eye very large and conspicuous in the living animal. 

 Anterior antennae rather slender, with the distal part exceeding half the length 

 of the proximal one. Posterior antennae less strongly built than in the 2 pre- 

 ceding species. Mandibular palp with the inner expansion of the basal part rather 

 narrow and prominent, outer ramus small, with only a single apical seta. Pos- 

 terior maxillipeds powerfully developed, with the hand large, sub-crescentic in 

 shape, and irregularly angular, palmar edge deeply concaved and defined in front 

 by a distinct projecting corner, dactylus very strong and curved. 1st pair of 

 legs much feebler in structure than in the 2 preceding species, both rami slender 

 and tapering distally, the outer one a little shorter than the inner, with the ter- 

 minal joint scarcely at all expanded, claws slender and quite smooth, the inner- 

 most one very much elongated, equalling in length the 2 preceding joints com- 

 bined; apical claws of inner ramus very unequal, the inner one much elongated, 

 the outer very small. Last pair of legs considerably smaller than in the 2 pre- 

 ceding species, distal joint oval in form, inner expansion of proximal joint rather 

 broad and extending considerably beyond the distal one. Ovisac generally very 

 large, pyriform. 



Male with the last pair of legs, as usual, less fully developed than in 

 female, distal joint rather small and having only 5 marginal setae, inner expansion 

 of proximal joint not nearly extending as far as the distal one, and carrying 3 

 unequal setse. 



Body semipellucid, of a light greenish hue and generally filled with clear 

 oil-bubbles. 



Length of adult female 1.14 mm. 



Remarks. This is a very distinct and easily recognizable form, being 

 especially distinguished by its slender and elongated body, as also by the struc- 

 ture of the posterior maxillipeds, and the 1st and last pairs of legs. 



