60 



lamellae of sub-quadrangular shape, and armed at the upper corner with 2 

 strong claw-shaped spines, lower corner produced to an acute prominence 

 accompanied below by a slender bristle. Anterior antennae angularly bent in 

 the middle, and composed of 9 well defined joints, the first 3 of which are 

 much larger than the others and have the seta? distinctly ciliated. Posterior 

 antennae rather strongly built and attached to the head by a short and thick 

 basal joint, terminal joint longer than the preceding one and finely ciliated on 

 both edges, apical claw only slightly curved and accompanied by 2 small bristles. 

 Mandibular palp with the basal part narrower than usual, inner ramus lamelli- 

 form, undivided, outer ramus more slender and provided in its outer part with 

 5 setae, the 2 outermost issuing from a small but well defined apical joint. 

 Endopodal part of maxillae with the terminal joint somewhat spatulate in form 

 and provided at the end with 3 setae. Anterior maxillipeds not particularly 

 strong and gradually tapered distally. Posterior maxillipeds forming each an 

 undivided oblong oval lamella clothed at the tip and inside with a number 

 of partly ciliated setae. The 4 anterior pairs of legs gradually somewhat 

 increasing in length, 4th pair with the outer ramus considerably longer than 

 the inner and having the terminal joint rather produced. Last pair of legs 

 with the proximal joint produced outside to a conical process tipped with a 

 slender bristle; distal joint very small and narrow, with a single apical seta. 



Body in the living animal rather pellucid, of a whitish grey hue with 

 the rather large ripe ova dark bluish or purplish. 



Length of adult female 2.10 mm. 



Male unknown. 



Remarks. The present form is at once distinguished from any of the 

 other known Doropygidae by its very slender and narrow body, the short and 

 abruptly bent tail, and the shape of the incubatory pouch. 



Occurrence. I have met with this form not unfrequently in several places 

 on the Norwegian coast. It is found in several kinds of Ascidians and, as 

 observed by Thorell, almost exclusively between the lamellae of the branchial 

 sac, more or less firmly attached to these lamellae by the aid of its powerful 

 posterior antennae. When loosened from its hold, the animal rests nearly 

 motionless on the bottom, only a slight bending of the body being perceptible. 



Distribution. Coast of Bohuslan (Thorell), British Isles (Brady). 



