94 



D. JAUME AND G.A. BOXSHALL 



0.05 mm 



Fig. 9. Euryte longicauda Philippi, 1843, adult male. A, antenna; B, mandible; C. maxillule praecoxal arthrite; D. maxillulary palp; E. maxilla; F, 

 maxilliped. 



Prosome about 1.4 times longer than urosome, comprising 

 cephalosome plus 4 free pedigerous somites; first pedigerous 

 somite completely concealed beneath posterior extension of 

 cephalosome, with lateral margins weakly sclerotized; second to 

 fourth somites with evenly rounded posterolateral corners. Ros- 

 trum (Fig. 8C) fused at base, well developed, subtriangular in 

 frontal view. Urosome 6-segmented; first abdominal somite with 

 pointed posterolateral angles; entire hyaline frill adorning 

 posterodorsal margin. Genital somite (Figs 8D,E) symmetrical, 

 laterally expanded, with entire hyaline frill around posterodorsal 

 margin; pair of gonopores opening ventrally at posterior border of 

 somite; opercular flaps each armed with 1 inner flanged spine plus 

 2 outer setae. Third to fifth urosome somites subequal, narrower 

 than genital somite, with entire hyaline frill adorning posterior 

 margin. Anal somite (Fig. 8F) about same size as preceding 

 somites; smooth anal operculum present at one third of distance 

 along somite; serrate hyaline frill around posterolateral margins of 



somite. Caudal rami (Fig. 8F) of variable length, from 4.4 to 6.4 

 times longer than wide, slightly divergent; distal part slightly 

 wider; armature consisting of 6 setae; seta II located subdistally. 



Antennules (Fig. 8G) 1 6-segmented, symmetrical, digeniculate 

 with geniculations between segments homologous with ancestral 

 segments XV and XVI (10 and 11), and segments XX and XXI (14 

 and 15). Segment 10 cup-shaped, forming sheath around proximal 

 half of segment 1 1 . Segmental fusion pattern and armature as 

 follows: Segment 1 (corresponding to fused ancestral segments I to 

 V), 8 setae + 3 aesthetascs; segment 2 (corresponding to fused 

 ancestral segments VI and VII), 4 setae; segment 3 (VIII), 2 setae; 

 segment 4 (IX), 2 + aesthetasc; segments 5 to 8 (X to XIII), 2 setae 

 each; segment 9 (XIV), 2 + aesthetasc; segment 10 (XV), 2 setae; 

 segment 11 (XVI), 2 + aesthetasc; segment 12 (XVII). 1 short 

 denticulate spine and 1 seta; segment 13 (XVIII), 1 short denticulate 

 spine, 1 seta + aesthetasc; segment 14 (fused ancestral segments 

 XIX and XX), 1 short denticulate spine, 1 modified flattened spine, 



