Clare Island Survey — Marine Entomostraca. 45 11 



y tapering. 1st antenna (PI. II 

 long ; proportional length of joints, 



uniformly tapering. 1st antenna (PI. II, fig. 1) eight-jointed, moderately 



25 . 24 . 18 . 22 . 12 .17.10. 15. 



1. 2. 3. 4. 5. 6. 7. 8 

 2nd antenna as usual in the genus, exopodite two-jointed, first joint 

 with one, and second with three setae. Mandible (PI. II, fig. 4j 

 with strongly denticulate cutting edge, three inner-edge setae on 

 second joint, exopodite very small with two setae, and endopodite with 

 two lateral and five terminal setae. Maxilla (PL II, fig. 3) with strongly 

 chitinized and denticulate inner basal lobe, which almost forms a second 

 mandible, distal portion feebly developed, but of usual form. 2nd maxilla 

 (PI. II, fig. 8) with three stout basal lobes as in Diosaccus, with short 

 spines. Maxillipede (PL II, fig. 9) with large concave hand and strong 

 claw as in Diosaccus, but comparatively smaller than in that genus. 

 1st pair of feet (PL II, fig. 5) as in Diosaccus rather than Amphiascus, 

 both branches being rather slender, and the two terminal joints of the 

 endopodite smaller than in Amphiascus. 2nd pair of feet, exopodite 

 with 1.1.3 outer-edge and one terminal spine, and 0.1.3 inner- 

 edge setae, endopodite with 0.0.1 outer-edge, one terminal and 

 1.2.2 inner-edge setae. 3rd pair of feet, exopodite with 1.1.3 

 outer-edge and one terminal spine, and 0.1.4 inner- edge setae, 

 endopodite with 0.0.1 outer-edge, one terminal, and 1.2.3 inner- 

 edge setae. 4th pair of feet similar to the 3rd, except that there 

 are only 1.1.3 inner-edge setae on the endopodite. 5th pair of feet 

 (PL II, fig. 6), small, with comparatively short spiniform setae, inner 

 extension of basal joint with five setae, distal joint with six setae. 

 The 6th pair of feet is represented by three fine setae on each side of 

 the front margin of the genital segment. 



Male, length 1-0 mm. 1st antenna of usual prehensile form. 1st pair 

 of feet with a short, blunt hook on the inner margin of the second basal 

 joint. Endopodite of 2nd pair of feet with the second joint terminated 

 by two strong spines and two very small setae. 5th pair of feet (PL II, 

 fig. 7) with two setae on the inner extension of the first joint, and 

 four on the second joint. 



Colour, second and third thoracic segments bright crimson, 

 abdomen yellow. 



This species might be mistaken for Amphiascus cinctus, which it 

 greatly resembles when fresh, but it may be distinguished by the 

 absence of the longitudinal dorsal band on the cephalon, and by the 

 abdomen being yellow instead of colourless. A few specimens have 

 been found of a uniform yellow colour. 



B2 



