20 



R. HUYS AND S. CONROY-DALTON 



the first abdominal somite in the male. Females of both species can 

 be differentiated by the ventral ornamentation pattern of the urosome 

 (C. gracilis has lateral spinular patches on the first postgenital 

 somite) and the ventral transverse chitinous ridge (marking the 

 original segmentation of the genital double-somite) which is more 

 strongly developed in C. gracilis. Giesbrecht ( 1 892) did not illus- 

 trate the second abdominal somite in the female, however, stated in 

 the text that spinules were present ventrally around the posterior 

 margin of all three postgenital somites. Caudal ramus seta IV is 

 distinctly shorter than seta V in females of C. gracilis (see also 

 Giesbrecht (1892): Taf. 45, Fig. 27; Sars (1921): Plate LXVIII), 

 while both setae are equally long in the female of the type species. 

 Both sexes of C. gracilis have a propensity for developing asymme- 

 try in the caudal rami whereby one ramus is markedly narrower than 

 the other (see also Claus (1891a): Taf. I, Figs 1-2; Giesbrecht 

 (1892): Taf. 45, Fig. 27). 



Despite his own arguments to the contrary, T Scott (1894) 

 inexplicably identified his clytemnestrid material from the Gulf of 

 Guinea as C. rostrata. A. Scott (1909) re-identified the material as 

 C. scutellata. Re-examination of the Buccaneer material (BMNH 

 1893.4.22.268-275) has revealed it to be an amalgamate of two 

 species, containing 9 99 and 1 6* of C. gracilis and 7 9? of a 

 smaller Goniopsyllus sp. This might explain the discrepancy found 

 between the body length reported by T. Scott (1.25 mm) and our 

 measurements (x = 1 .44 mm). Since males are usually larger than 

 females (Giesbrecht, 1892) it is doubtful whether Marques' (1973) 

 male specimen (0.99 mm) of C. scutellata from Sao Tome (Gulf of 

 Guinea) belongs to C. gracilis. 



The only illustrated record of C. scutellata from northern Europe 

 is that by Sars (1921) who found a single female in Oslofjord and 

 described it in great detail. His specimen, 1 .24 mm in length, agrees 

 in all aspects with C. gracilis and represents a significant range 

 extension for this species. Kasturirangan (1963) reproduced 

 Giesbrecht's (1892) and Sars' (1921) drawings of C. gracilis in his 

 identification key to the planktonic copepods of Indian coastal 

 waters, however its presence in the Indo-Pacific has yet to be 

 confirmed. 



Vilela (1968) reported two females of C. scutellata, measuring 

 1.24-131 mm, from the Portuguese coast off Lisbon. Her illustra- 

 tions of the caudal rami and P5 positively identify her material as C. 

 gracilis. 



Clytemnestra farrani sp. nov. 



Type LOCALITY. Great Barrier Reef, Queensland, Australia. Farran 

 (1936) recorded a total of 5 specimens (4 belonging to C. farrani, 1 

 to C. longipes) from serial townettings (his stations 62, 65, 68) at 3 

 miles east of the laboratory on Low Island (off Port Douglas); depth 

 32 m. 



ETYMOLOGY. This patronym commemorates the late G.P. Farran 

 for his comprehensive contributions to our knowledge of planktonic 

 copepods. 



TYPE MATERIAL. Holotype $ dissected on 6 slides (BMNH 

 1999.998); paratypes are 1 9 and 2 66 in alcohol (BMNH 1999. 

 999-1001). This material was originally registered as C. scutellata 

 under reg. no. 1948.4.28.121. Collected during Great Barrier Reef 

 Expedition 1928-29 on either 15 June (stn 62), 10 July (stn 65) or 1 8 

 July 1929 (stn 68). 



Other material examined. From R. Bottger-Schnack: 1 9 in 

 alcohol (BMNH 1999.1065); southern Red Sea, Meteor cruise 5/5, 

 stn 703 ( 15°34.8' N, 41°54.9' E); 03 August 1987; multiple opening- 



closing net, 0.055 mm mesh, vertical hauling, 0-50 m (total water 

 depth 970 m). 



Description. 



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

 of caudal rami: 927-946 urn (x = 937 urn; n = 2). Maximum width 

 (252 urn) measured halfway the cephalic shield length. Posterola- 

 teral angles of cephalothorax rounded, not expanded (Fig. 12A). 

 Backwardly produced alate processes of somites bearing P2-P4 

 distinctly shorter than in C. scutellata and C. gracilis. 



Genital double-somite (Fig. 13A) not constricted bilaterally; 

 original segmentation marked by small, paired, chitinous patches 

 lateroventrally. Genital field as in type species. 



Urosomites without dorsal ornamentation; penultimate and anal 

 somites with multiple rows or patches of minute spinules around 

 ventral hind margin and with lateroventral spinular patches on 

 second abdominal somite (Fig. 13 A). 



Caudal rami (Fig. 13A, C) shorter than in previous species; setae 

 IV slightly shorter than seta V but both setae distinctly shorter than 

 in C. scutellata (only slightly longer than ramus and as long as seta 

 III) and minutely pinnate. 



Rostrum (Fig. 12A) rounded anteriorly, obtuse. 



Antennule 7-segmented, with armature formula as in type species. 

 Antenna, mouthparts (proximal endite on maxillary syncoxa present) 

 and maxillipeds as in type species. 



P2 exp-3 with only 2 outer spines (Fig. 9C). P2-P4 armature 

 formula: 



exopod 



endopod 



P2 

 P3 

 P4 



1.1.222 

 1.1.323 

 1.1.323 



1.2.221 

 1.2.321 

 1.2.221 



P5 (Fig. 9D) extending to posterior margin of genital double- 

 somite. Basis short, exopod about 3 times as long as basis, with 5 

 setae (3 outer, 1 apical, 1 inner). 



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

 caudal rami: 939-945 urn (x = 942 urn; n = 2). Maximum width (257 

 urn) measured at posterior margin of cephalic shield. Body (Fig. 

 12B) with similar projections as in 9; urosome more slender with 

 genital and first abdominal somites separate (Fig. 13B). 



Antennule, antenna, mouthparts and maxilliped with armature as 

 in C. scutellata. 



P5 (Fig. 9E) distinctly shorter than in 9, not extending to distal 

 margin of first abdominal somite; exopod 1.9 times as long as basis, 

 apical and inner setae shorter than in 9. 



Sixth pair of legs (Fig. 13B) weakly asymmetrical; each P6 

 produced into short cylindrical process with 1 outer and 2 apical bare 

 setae. 



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

 margin (Fig. 13B). 



Caudal rami (Fig. 13B) stubbier than in 9; setae I — II bare; setae 

 IV-V very long (95% of urosome length) and plumose; seta VI 

 much longer than in 9. 



Remarks. C. farrani can be readily distinguished from its conge- 

 ners by the swimming leg setal formula, showing only 2 outer spines 

 on P2 exp-3 but 3 outer spines on P3-P4 exp-3. It is closely related 

 to C. asetosa which resembles it in the small size, the absence of 

 posterolateral processes on the cephalothorax and the presence of 

 only 5 setae on the P5 exopod. The number of endites on the 

 syncoxa, the spinulation pattern on the female urosome and the 



