12 



R. HUYS AND S. CONROY-DALTON 



developed praecoxa; both without ornamentation. Rami 3-segmented 

 except for PI exopod. 



PI (Fig. 6A) separated from maxillipeds by large membranous 

 area. Coxa and basis prolonged along dorsoventral axis; without 

 surface ornamentation. Basis with plumose outer spine. Exopod 1- 

 segmented, represented by elongate segment bearing long setules 

 along outer margin; with subapical pore and 1 outer, 2 apical and 1 

 inner setae. Endopod 3-segmented; segments decreasing in size 

 distally, each with anterior pore; enp-1 and -2 with few setules along 

 outer margin, enp-2 and -3 with posterior spinules; enp-1 with very 

 long inner seta; ornamentation of inner elements typically 

 (multi)pinnate, distal elements of enp-3 plumose. 



P2-P4 (Figs 6B; 7 A, B) with transversely prolonged basis bearing 

 short outer seta. Endopods distinctly longer than exopods. Exopodal 

 outer spines setiform with flagellate tip. Exopod segments typically 

 with pore near outer distal corner; without ornamentation; exp-2 

 outer distal corner linguiform. Endopods with long proximal seg- 

 ment, particularly in P2-P3; segments with anterior pore, setules 

 along outer margin and spinules on posterior surface; setal ornamen- 

 tation typically combination of setular and spinular rows; inner seta 

 of P2-P3 enp-1 short. PI exp-2 without outer spine. Spine and setal 

 formula of swimming legs as follows: 



Exopod 



Endopod 



PI 



P2 

 P3 

 P4 



121 



1.1.223 

 1.1.323 

 1.1.323 



1.1.220 

 1.2.221 

 1.2.321 

 1.2.221 



P5 (Fig. 1C) uniramous, laterally displaced; 2-segmented; not 

 extending beyond posterior margin of genital double-somite (Fig. 

 5A). Basis with short outer seta and anterior pore. Exopod about 

 twice as long as basis, slightly curved inwards; outer margin with 4 

 pinnate setae; inner margin with long plumose seta; apex and inner 

 margin each with 1 long pinnate seta; anterior surface with 3 pores 

 and spinules near apex and in proximal third. 



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

 caudal rami: 1064 urn. Maximum width (337 um) measured at 

 posterior margin of cephalic shield. Body (Fig. IB) with similar 

 projections as in 9; urosome more slender with genital and first 

 abdominal somites separate (Fig. 5B). 



Rostrum (Fig. IB) more obtuse than in 9. 



Antennule (Fig. 2B) slender, distinctly 7-segmented with ances- 

 tral segment XIII completely incorporated into segment 4 (Fig. 2C); 

 haplocer, with geniculation located between segment 6 and 7. 

 Plumose setae present on segments 1-4. Segment 1 with small pore 

 near seta and few tiny spinules along anterior margin. Armature 

 formula: 1-[1 plumose], 2-[8 + 3 plumose], 3-[5 + 3 plumose + 1 

 pinnate + 1 transformed + ae], 4-[2 + 3 plumose + (1 transformed + 

 ae)], 5- [1 + 1 spine], 6-[2], 7-[9 + 2 modified elements + acrothek]. 

 Apical acrothek consisting of aesthetasc, long transformed seta and 

 short bare seta. Transformed setae on segments 3, 4 and 7 long and 

 aesthetasc-like, with rounded tip; those on segments 4 and 7 basally 

 fused to aesthetasc. Rudimentary element present at base of acrothek 

 (arrowed in Fig. 2F). Segment 6 with 2 patches of spinules on 

 anterior surface (Fig. 2D-E). Segment 7 with 2 fused elements near 

 geniculation (Fig. 2D). 



Maxilliped (Fig. 4C) much larger than in 9, articulating with well 

 developed pedestal; 3-segmented, comprising syncoxa, basis and 

 endopod. Syncoxa extremely elongate but not distinctly longer than 

 basis; without ornamentation but with 1 short anterior 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 single row of spinules on both 

 anterior and posterior sides; with 2 elements located closely to 

 articulation with endopod; proximal element spiniform and bare 

 (arrowed in Fig. 4D), distal element pad-like and spinulose. Endopod 

 represented by short segment produced 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; 

 accessory armature consisting of 3 anterior and 2 posterior setae; 

 claw with spatulate apex. 



P5 (Fig. 7C) very similar to that of 9, with identical proportions, 

 pore pattern and setation. 



Sixth pair of legs (Fig. 5B) weakly asymmetrical, forming highly 

 membranous midventral area covering single, large median genital 

 aperture; each P6 produced into cylindrical process (Fig. 5C) with 1 

 apical and 2 outer bare setae; few spinules along inner margin. 



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

 margin (Fig. 5B). 



Caudal rami (Fig. 4F) somewhat shorter than in 9; seta II rela- 

 tively longer; seta III more slender and with longer pinnules; setae 

 IV-V long (60% of urosome length; Fig. 5B) and plumose; seta VI 

 much longer than in 9 and sparsely plumose. 



Spermatophore with very long, recurved neck. 



Variability. The right distal exopod segment of the male P2 has 

 only 2 outer spines (Fig. 6C). 



Remarks. There are very few published records of C. scutellata 

 that can be verified absolutely. There is little doubt that the species 

 described by Poppe (1891) under the name C. hendorffi is synony- 

 mous with C. scutellata. Poppe's detailed description shows similar 

 posterolateral projections on the cephalothorax which are absent in 

 the other species from the Great Barrier Reef. C. hendorffi also 

 shows great consistency in body size (9: 1.09 mm; 6": 1.07 mm), 

 relative proportions of the caudal rami and P5, and the ventral view 

 of the female urosome demonstrates the absence of spinular patches 

 on the second abdominal somite. The only significant discrepancy is 

 found in the armature of the P2 exopod which Poppe had figured 

 with an outer spine on the proximal segment. The absence of this 

 element is a generic character and we suspect that Poppe had 

 assumed its presence to be the rule in clytemnestrids and had altered 

 his figure accordingly. Poppe's (1891) material came from two 

 localities in the Indian Ocean (West Australian Basin, south of 

 Madagascar), three localities in the southwest Atlantic off the coasts 

 of Brazil and Argentina, and the Karimata Strait in the Java Sea. He 

 also re-identified Thompson's (1888) material of Goniopsyllus 

 rostratus from the Maltese Sea as C. hendorffi, confirming its 

 presence in the Mediterranean. From a zoogeographical point of 

 view (see below) it appears more conceivable that Thompson had 

 collected the species described by Claus (1891a) under the name 

 Goniopelte gracilis, the description of which was unknown to Poppe 

 (1891). We have been unable to confirm the presence of C. scutellata 

 in the Atlantic or the Mediterranean and therefore suspect that 

 Poppe's records from the southwest Atlantic might have been based 

 on another species, possibly C. gracilis. Poppe based his illustra- 

 tions on specimens from the West Australian Basin, suggesting an 

 Indo-Pacific distribution pattern for C. scutellata. 



The redescription by Giesbrecht ( 1 892) has long been accepted as 

 the basis for identification of C. scutellata even though his material 

 was not from the type locality. However, from our revision it is clear 

 that Giesbrecht had redescribed Goniopelte gracilis (see below). 

 Both species are closely related, sharing the posterolateral projec- 

 tions on the cephalothorax and the presence of 3 outer spines on 



