36 THE VOYAGE OF H.M.S. CHALLENGER. 



Since the above was written I have received from ]\Ir. Dendy a number of other 

 specimens of this species from Station 320 (600 fathoms). They were found upon 

 two species of Sponges, Esperella lapidiformis, Ridley and Demly, and upon (,'c!lins 

 carduus, var. hvvis, Ridley and Dendy. The specimens agreed very closely with the 

 type described above, the only difference being that in one individual there were traces 

 of eyes in the shape of two crystalline cones, together with the corresponding pig- 

 mented retinal cells. This forms another instance of a shallow-water species ranging 

 into deep water. 



Astrurus, F. E. Beddard. 

 Astrurus, F. E. Beddard, Proc. Zool. Soc. Lond., 1886, pt. i. p. 99. 



Generic Character. — Body narrow, oval, tapering posteriorly, even- where densely 

 beset with short spines ; head terminating in front in a long bifid rostrum ; i 

 absent (?) ; head and four anterior segments of the thorax furnished with a long spine 

 on either side, covered with minute spines, similar to those which cover the body ; tli 

 posterior segments of thorax with a pair of much smaller spines ; abdominal segments 

 with the exception of the first fused into a single piece which is pear-shaped ; it 

 terminates behind in four curved short spines arranged like a cross ; antennules short ; 

 four joints on the peduncle with a two or three-jointed flagellum ; antennae more than 

 half the length of the body ; the two distal joints of the peduncle are elongated ; 

 the flagellum is about as long as the last joint. Mandibles with a long palp consisting 

 of three joints. Anterior pair of thoracic limbs prehensile in form. Posterior pairs of 

 thoracic appendages elongated; thoracic limbs terminating in a single claw. Uropoda 

 consisting of a single conical joint, very short, with a minute distal joint. 



Remarks. — This genus is closely allied to Munna, Paramunna, Leptaspidia, 

 and Pleurogonivm, it perhaps comes nearest to the two last mentioned genera ; it 

 agrees with Leptaspidia and Pleurogoniwm in the general shape of the body. With 

 Leptaspidia, Astrurus corresj)onds in the form of the antennary organs and of tin 

 uropoda; in Leptaspidia, however, the thoracic appendages are not so elongated as 

 in Astrurus, and in this feature of its organisation the latter genus presents affiniti 

 to Munna and Dendrotion ; Munna, however, differs from Astrurus in having two 

 claws at the termination of the thoracic appendages ; there is only one in Astrurus, as 

 in Pleurogonium and the other genera that have been mentioned ; if I am right in 

 describing the two lateral projections of the head with their orange-coloured contents 

 as eyes, this genus will present another strong point of resemblance to J/-/, ma, and 

 especially to Acanthomunna. 



