59 



24. Diaixis hibernica (A. Scott). 



(PI. XXXIX & XL). 



Scolecithrix hibernica, Andr. Scott, Ann. Nat. Hist., 6th series, Vol. 18, 



p. 362, PI. XVII & XVIII. 



Specific Characters. Female. Anterior division of body, seen dorsally, 

 elliptical in form, greatest width not attaining half the length, anterior extremity 

 narrowly rounded, posterior considerably contracted ; seen laterally evenly vaulted 

 above and somewhat widening anteriorly, dorsal margin curving abruptly in front, 

 rostral prominence conical in form and extended straight downwards. Last seg- 

 ment of metasome very short and deeply emarginated in the middle, lateral pro- 

 jections irregularly triangular, and defined above by a slight incision of the margin, 

 being closely applied to the genital segment, to the end of which they extend. 

 Urosome not attaining even V 3 of the length of ^the anterior division, genital 

 segment with a very conspicuous gibbous prominence dorsally. Caudal rami 

 somewhat longer than they are broad, and slightly dilated distally, each with a 

 small dentiform projection outside the apical setae, the latter but very slightly 

 divergent and somewhat exceeding the urosome in length. Anterior antennae, 

 when reflexed, reaching about to the end of the genital segment. Posterior 

 antennae with the outer ramus more than twice the length of the inner. Anterior 

 maxillipeds with about 5 vermiform appendages at the tip. Posterior maxillipeds 

 with the terminal part scarcely exceeding '/s f the length of the 2nd basal joint. 

 Natatory legs successively increasing in length posteriorly, 4th pair very slender, 

 with the terminal joint of outer ramus almost linear in form, and having the 

 proximal spine of the outer edge placed beyond the middle. 



Male on the whole resembling the female in the general shape of the 

 body, but having the last \segment of metasome very small and not produced laterally. 

 Urosome more slender, and as usual 5-articulate, last segment very short. Last pair 

 of legs, when reflexed, reaching far beyond the tips of the caudal setae, basal part 

 with a comb-like series of about 5 curved spines on the left side; right ramus 

 somewhat band-like, irregularly flexuous and carrying on the tip a movable hand- 

 like piece produced into 2 digitiform processes, left ramus 4-articulate, with the 

 2nd joint the largest and produced outside into several irregular projections, last 

 2 joints comparatively short and somewhat lamellar, the terminal one carrying 

 inside a slender flexuous seta and 2 short spines. 



Colour. Body in both sexes pellucid, with a faint carneous tinge, and 

 partly mottled with a pale rose pigment. 



Length of adult female 1.20 mm., of male 1.10 mm. 



