40 



R. HUYS AND S. CONROY-DALTON 



spinular rows; inner seta of P2-P3 enp-1 short. Spine and setal 

 formula of swimming legs as for genus. 



P5 (Fig. 24C) uniramous, laterally displaced; 2-segmented, com- 

 prising basis and 1 -segmented exopod; not extending to distal 

 margin of genital double-somite (Fig. 23A). Basis with short outer 

 seta and pore near outer distal corner. Exopod about twice as long as 

 basis, slightly curved inwards; outer margin with 2 pinnate setae and 

 3 pores; inner margin with long plumose seta; apex with 1 pinnate 

 and 1 plumose seta. 



male. Total body length from tip of rostrum to posterior margin of 

 caudal rami: 1021 urn (n = 1). Maximum width (304 um) measured 

 at posterior margin of cephalic shield. 



Body (Fig. 25A) with similar projections as in 9; genital and first 

 abdominal somites separate. 



Rostrum (Fig. 25A) more pointed than in 9. 



Antennule (Fig. 20C) slender, indistinctly 7-segmented with seg- 

 ment 4 only demarcated dorsally (Fig. 20D); haplocer, with 

 geniculation located between segment 6 and 7. Plumose setae 

 present on segments 1-5. Segment 1 with small pore near seta and 

 few long setules along anterior margin. Armature formula: 1-[1 

 plumose], 2-[5 + 5 plumose], 3-[5 + 1 plumose + 1 pinnate + 1 

 transformed + ae], 4- [2 plumose], 5-[4 plumose + 1 pinnate+ (1 

 transformed + ae)], 6-[l + 2 pinnate spines + 1 smooth spine], 7-[10 

 + 2 vestigial elements + acrothek]. Apical acrothek consisting of 

 aesthetasc, long transformed seta and short bare seta. Transformed 

 setae on segments 3, 5 and 7 long and aesthetasc-like, with minutely 

 spiniform tip; those on segments 5 and 7 basally fused to aesthetasc. 

 Rudimentary element present at base of acrothek (arrowed in Fig. 

 20E). Segment 6 with continuous patch of spinules on anterior 

 surface (Fig. 20D). Segment 7 with 2 vestigial elements near 

 geniculation. 



Maxilliped (Fig. 22E) very large, articulating with well devel- 

 oped pedestal; 3-segmented, comprising syncoxa, basis and endopod. 

 Syncoxa extremely elongate but not longer than basis; without 

 ornamentation but with 1 anterior, plumose seta near membranous 

 articulation with basis. Basis elongate; more swollen than in 9; 

 middle and distal thirds of palmar margin forming longitudinal 

 furrow bordered by multiple rows of spinules on both anterior and 

 posterior sides; with 2 elements located closely to articulation with 

 endopod; proximal element spiniform and bare, distal element 

 stubby and spinulose. Endopod represented by short segment pro- 

 duced into very long naked claw which in reflexed position typically 

 fits in palmar furrow with the apical part closely adpressed onto the 

 anterior surface of the basis (Fig. 22E, G); accessory armature 

 consisting of 3 anterior setae and 2 posterior setae (Fig. 22F-H). 



P5 (Fig. 25C) very similar to that of 9, with identical proportions 

 and setation but lateral setae of exopod slightly shorter. 



Sixth pair of legs (Figs 11C; 26B) asymmetrical, represented by 

 highly membranous non-articulating flaps covering single, large 

 genital aperture (Fig. 1 1C); each lobe with 1 bare seta at outer distal 

 corner. 



Urosomites 4-5 and anal somite with spinules around ventral hind 

 margin (Fig. 26B). 



Caudal rami (Fig. 26B) slightly more slender than in 9; conical 

 projection wider and setae I — II relatively shorter. 



Spermatophore with very long, recurved neck (Fig. 26B). 



VARIABILITY. The left P5 of the holotype 9 shows slightly 

 different segmental proportions and pore pattern (Figs 23A; 24D). 



Remarks. This species was illustrated by Huys et al. (1996) as 

 'Clytemnestra ro strata' . Their brief description which was based on 

 material from the Gulf of Cadiz contains some observational errors. 



The most significant is the setation of the maxillule which was 

 actually based on C. gracilis. The armature on the genital field was 

 omitted in their Fig. 120B. The female P5 (their Fig. 121C) also 

 appears shorter but this is to be regarded as the result of excessive 

 squashing during mounting. 



The distribution of G. clausi is thus far restricted to the Portu- 

 guese coast (Vilela, 1965, 1968) and the Mediterranean with 

 confirmed records from the Bay of Cadiz, Naples and the Adriatic. 

 Sapphir rostratus has also been recorded from the Adriatic but is 

 probably not synonymous with G. clausi (see below). The Naples 

 record refers to Giesbrecht (1892) who found 1 6 of 'C. rostrata' in 

 this area but also attributed Pacific specimens (3 99, 2 66) to this 

 species. 



Goniopsyllus rostratus Brady, 1883 



Clytemnestra rostrata (Brady, 1883) Poppe (1891) 



TYPE LOCALITY. South Atlantic, off Argentinean coast; 42 c 32' S 

 56°29' W; net at 54 m depth. 



Material examined. Holotype 9 dissected on slide (reg. no. 

 C.C.46); collected during Voyage of H.M.S. Challenger during the 

 years 1873-1876 (station 318); 11 February 1876. The dissection is 

 imperfect and incomplete (e.g. antenna and PI are lacking), and the 

 specimen is partly aberrant in the swimming leg setal formula. 



Redescription. 



female. Genital double-somite (Fig. 28A) relatively short in 

 comparison with other species, not constricted bilaterally; original 

 segmentation marked by two minute chitinous patches ventrally. 

 Copulatory pore (Fig. 28A) located medially in large circular de- 

 pression, halfway the length of genital double-somite; leading to 

 anteriorly directed, strongly chitinized duct which at level of PS- 

 bearing somite enters median seminal receptacle. Genital apertures 

 located far anteriorly; closed off by small opercula derived from 

 vestigial P6; each with 1 well developed seta. 



Urosomites with zone of small denticles around dorsal hind 

 margin; penultimate and anal somites also with larger spinules 

 around ventral hind margin (Fig. 28A). 



Caudal rami short (Figs 26G; 28A), convergent; similar in shape 

 to G. clausi but proportionally smaller. Setae I — II bipinnate, spiniform 

 and strongly developed; seta 1 1.7 times as long as seta II, extending 

 beyond apex of caudal ramus. Seta III minutely bipinnate. Setae IV- 

 V basally fused, without fracture planes, multipinnate and more 

 setiform and distinctly longer than in G. clausi (compare Fig. 23B); 

 seta V about 3 times ramus length. Seta VI minute, bare; seta VII 

 Particulate at base, bare. 



Antennule (Fig. 26A) slender, 6-segmented; segment 6 longer 

 than in G. clausi (length ratio segment 6 : segment 5 being 6.0 in G. 

 rostratus, 5.0 in G. clausi). Armature pattern as in G. clausi. 



Maxilliped (Fig. 26D) with similar armature as in G. clausi but 

 with different spinular ornamentation on palmar margin (Fig. 26E). 



P2-P4 spine and setal formula of swimming legs as follows (left 

 P3 exp-3 and right P4 exp-3 with aberrant outer spine number): 



Right 



Exopod 



Left 



Endopod 



P2 

 P3 

 P4 



1.1.222 

 1.1.323 



1.1.322 



1.1.222 

 1.1.322 

 1.1.323 



1.2.221 

 1.2.321 

 1.2.221 



P5 (Fig. 26F) 2-segmented, comprising basis and 1 -segmented 

 exopod;relative lengths as in G. clausi. Exopod outer margin with 2 



