REVISION OF DANIELSSENIA AND PSAMMIS 



67 



row of long setules at 1/3 distance from the proximal margin, 

 and 1 lateral, 1 subapical and 2 apical setae. 



Maxillule (Fig. 15C). Praecoxal arthrite with 9 spines and 1 

 tubular seta around the distal margin, and 2 geniculate 

 tubular setae on the anterior surface; coxal endite with 1 

 pinnate spine, 1 setulose claw, 1 smooth setae and 3 tubular 

 setae; basal endites closely set, proximal with 2 setae, distal 

 with 2 setae and 2 spines; rami with 3 setae each. 



Maxilla (Fig. 15D). Praecoxal endite with 2 unilaterally 

 pinnate spines and 1 basally fused spine bearing tubular 

 extension. Coxal endites with 1 spine and 2 tubular setae 

 each. Allobasis with 2 articulating claws, 1 pinnate spine and 

 1 tubular seta. Endopod with 1 tubular seta, 1 spine and 2 

 pinnate setae. 



Maxilliped (Figs 15E-F). Syncoxa with 1 large setulose 

 spine posteriorly and 1 smaller pinnate seta anteriorly. Basis 

 with anterior row of long spinules and small, pinnate seta on 

 palmar margin. Endopodal claw with 2 accessory setae. 



Intercoxal sclerites of P2-P4 (Fig. 16H) not U-shaped and 

 provided with large spinules on anterior surface (as in Archis- 

 enia). 



P2 endopod of male (Figs 16A-B). Inner setae of proximal 

 and middle segments reduced compared to the female. Outer 

 apophysis of middle segment very large, reaching far beyond 

 the distal segment. Inner setae of distal segment spiniform 

 and stouter than in the female; inner terminal seta reduced, 

 with spatulate tip; outer terminal seta represented by small 

 setule; outer spine curved at tip and standing on cylindrical 

 process. 



P3 endopod of male (Fig. 16C) with acutely recurved 

 process anteriorly at outer distal corner of middle segment. 



Genital field with minute copulatory pore (Fig. 16D) 

 leading via short sclerotized duct to multi-chambered seminal 

 receptacle (Figs 16F-G). Copulatory duct entering unpaired 

 ventral chamber leading dorsally to paired reservoirs both 

 anteriorly and posteriorly. Anterior reservoirs largest and 

 extending to posterior part of P5-bearing somite (Fig. 16D). 

 P6 in female represented by 1 plumose seta and 2 minute 

 spiniform elements (Fig. 16E). P6 of male with 1 plumose and 

 1 pinnate seta (Fig. 16J). 



Remark. Shen & Bai (1956) pointed out that either 1 or 2 

 setae can be found on the middle endopod segment of P2, 

 however, their figured specimen with 2 setae on this segment 

 (Plate XI, Fig. 86) is almost certainly an aberrant case. The 

 same applies to the armature of the baseoendopod of the 

 male specimens reported on by Gee (1988b) where a 'vari- 

 able' number of setae can be found; all setation patterns 

 diverging from the typical bisetose condition are aberrations 

 caused by abnormal copepodid development. 



(v) Amended diagnosis 



As a result of the arguments put forward above, the genus 

 Danielssenia now contains only 3 well defined species and we 

 have re-diagnosed the genus accordingly: 



Paranannopidae. Body variable in size, slightly fusiform 

 and dorso-ventrally flattened. Rostrum hyaline, large, typi- 

 cally deflexed, with 2 pairs of small sensillae. Somatic hyaline 

 frills minutely dentate except for deeply incised frill on dorsal 

 margin of P5-bearing somite. Original segmentation of 

 female genital-double somite marked by complete sub- 

 cuticular ridge; genital field with small copulatory pore; short 

 copulatory duct leading to seminal receptacle with paired, 



anteriorly directed chambers extending to anterior margin of 

 genital double-somite; P6 with 1 outer plumose seta and 2 

 minute spiniform elements. Pseudoperculum hyaline with 

 deeply incised margin. Caudal rami parallel, broader than 

 long, seta I minute. Female antennule 4-segmented; aes- 

 thetasc on segment 3; terminal segment with strong pinnate 

 spines. Antennary exopod 3-segmented with armature for- 

 mula [1-1-3]. Mandibular coxa with blunt teeth and 1 seta on 

 gnathobase, basis broad with 3 setae on distal margin; 

 endopod 1-segmented; exopod 1-segmented, with 1 lateral 

 and 3 distal setae. Maxillule with 3 tubular setae, 1 pinnate 

 seta and 1 spine on coxal endite; basal endite with 4 setae and 

 1 spine. Maxilla with tubular setae on coxal endites, allobasis 

 and endopod; praecoxal endite with 3 pinnate spines. Maxil- 

 liped subchelate with 1 large and 1 small seta on syncoxa; 

 basis with small pinnate seta on palmar margin, endopodal 

 claw with 2 accessory setae. PI exopod 3-segmented, exp-3 

 with distal outer spine longer than middle outer spine; 

 endopod 2-segmented, enp-2 4 times longer than broad, inner 

 seta implanted medially. P2-P4 intercoxal sclerites with 

 spinules on distal margin; rami 3-segmented; exp-1 without 

 inner seta. Armature formula of P1-P4 as follows: 



Exopod 



Endopod 



PI 



0.1.023 



1.121 



P2 



0.1.(1-2)23 



1.1.221 



P3 



0.1.(1-2)23 



1.1.(1-2)21 



P4 



0.1.(2-3)23 



1.1.(0-1)21 



Female fifth pair of legs not fused medially; exopod and 

 baseoendopod separate, each with 4 or 5 setae. 



Male with sexual dimorphism on antennule, P2 endopod, 

 P3 endopod, P5, P6, and in genital segmentation. Antennule 

 8- to 9-segmented, subchirocer; segment 6 very swollen, with 

 aesthetasc. P2 enp-2 with inner seta, outer distal corner 

 attenuated into a long apophysis reaching far beyond the 

 distal border of enp-3; enp-3 with distal outer spine and 2 

 terminal setae very reduced, inner setae spiniform and larger 

 than in female. P3 enp-2 with outer distal corner attenuated 

 into a recurved apophysis. P5 of each side fused medially; 

 baseoendopod and exopod separate with 2 and 4 or 5 setae, 

 respectively. P6 symmetrical, fused to somite, with 2 setae 

 each. 



Type species. D. typica Boeck, 1872 (by monotypy). [syn.: 

 D. fusiformis (Brady, 1880) sensu Sars (1910)]. 



Other species. D. quadriseta Gee, 1988; D. reducta Gee, 



1988. 



Species inquirenda. D. similis Chislenko, 1971. 



Key to species 



1. P2-P3 exp-3 with 2 inner setae, P4 enp-3 with 1 inner seta ... 2. 

 P2-P3 exp-3 with 1 inner seta, P4 enp-3 without inner seta 

 D. reductaGee, 1988. 



2. P3 enp-3 with 2 inner setae, P5 exopod with 5 setae in both sexes 



D. typica Boeck, 1872. 



P3 enp-3 with 1 inner seta, P5 exopod with 4 setae in both 

 sexes D. quadriseta Gee, 1988. 



