CRUSTACEA MALACOSTHACA. II. 63 



Abdomen slightly broader than seventh thoracic segment, as long as seventh, sixth and half 

 of the fifth thoracic segment combined. -- Uropods short (fig. 4f); endopod rather robust, two-jointed, 

 with the proximal joint distinctly longer than the distal; exopod nearly as long as the endopod, but 

 more slender and without any perceptible articulation. 



Length of the single specimen 1.85 mm . 



Remarks. T. solidus is easily distinguished from the other species by its broad body and the 

 shape of the thoracic segments; antennulse, chelipeds and uropods afford further characters. The ani- 

 mal is yellow, and its exoskeleton seems to be more solid than in any other species of similar size. 

 The specimen has the ventral side of the thoracic segments flat, consequently no ventral process on 

 second segment, and seems to be full-grown. 



Occurrence. Taken by the "Ingolf" at a single station. 



South-West of Iceland: St. 78: L,at. 60 37' N., Long. 27 52' W., 799 fm., temp. 4.5; i spec. 



Agathotanais n. gen. 



Body in the female and subadult male moderately slender, decreasing in breadth from the 

 middle of the carapace to the base of abdomen, which is narrower than the last thoracic segment. 

 Carapace about as long as the two following segments combined. No eyes. Antennulse in the female 

 three-jointed, with the first joint longer than the two others combined; in the subadult male the third 

 joint has a transverse suture. Antennae in the female (PI. VI, fig. 50) quite rudimentary, consisting of 

 a minute joint; in the subadult male (fig. 5 n) about as long as the proximal depth of the antennulse. 



Mandibles (fig. 5 d) small, with only the incisive part developed, while a movable lacinia and 

 the molar process are completely wanting. Maxillulse (fig. 5 f) consist of a single slender joint curved 

 towards both ends; the terminal part has several thick spines and some fine hairs; the palp is only 

 half as long as the joint, slender and very thin-skinned, with two terminal setae. (Maxillae not seen, 

 rudimentary or wanting.) Maxillipeds (fig. 5 g) considerably reduced; the two proximal joints and the 

 lobes are completely fused, constituting a circular, vaulted, strongly chitinized plate with a median 

 fissure in its anterior part; the four-jointed palps with the terminal joint slender; the epipods omit- 

 ted in the figure are subtriangular, small, thick plates. 



Chelipeds slender. Thoracic legs very slender; second and third pairs completely similar; claw 

 on the three posterior pairs very long (fig. 5 k). Seventh thoracic segment immovably fused with the 

 abdomen and all abdominal segments immovably fused, but all seven segments are limited by moder- 

 ately distinct, though feeble furrows (figs. 5b and 50). Pleopods wanting in the female (fig. 5b); in 

 the subadult male (fig. 50) they are long, unjointed, slender and somewhat conical and all coalesced, 

 constituting a kind of pyramid with longitudinal impressions between the pairs; each pleopod ter- 

 minates in a few very short setae. Uropods rudimentary, each being a small, subtriangular joint with- 

 out any distinct division (figs. 5! and 5m). 



The exoskeleton of the animals, excepting the walking legs, has a peculiar aspect and seems 



