REVISION OF DANIELSSENIA AND PSAMMIS 



Genus Bathypsammis gen. nov. 



Synonymy. Psammis Sars, 1910 (part.). 



Diagnosis. Paranannopidae. Body large, more or less cylin- 

 drical. Rostrum not hyaline, with 2 pairs of sensillae, anterior 

 pair large. Somatic hyaline frills minutely dentate. Female 

 genital double-somite with lateral and ventral sub-cuticular 

 ridge, marking original segmentation; copulatory pore 

 minute; copulatory duct and seminal receptacle unconfirmed; 

 P6 with 2 setae and 1 setule in between. Pseudoperculum 

 hyaline, vestigial. Caudal rami divergent, elongate (length 

 about 5 times proximal width); with tuft of long setules near 

 inner distal corner; dorsal surface with chitinized rim in 

 anterior half. Female antennule 4-segmented; aesthetasc on 

 segment 3; distal 2 segments with heavily pectinate spines. 

 Antennary exopod 3-segmented with armature formula 

 [2-1-3]. Mandibular coxa elongate, gnathobase with blunt 

 teeth and spinule row; basis broad with 4 setae on distal 

 margin; endopod 1-segmented, slightly longer than exopod; 

 exopod 1-segmented with 1 lateral and 2 apical setae. Maxil- 

 lule without modified spines on coxal endite; basal endite 

 with 5 setae. Maxilla without tubular setae; praecoxal endite 

 with 3 pinnate spines (1 fused to endite). Maxilliped subche- 

 late; armature of syncoxa unconfirmed; basis with naked seta 

 on palmar margin, endopodal claw with 2 accessory setae. PI 

 with very long outer basal seta reaching to middle of exp-3; 

 exopod 3-segmented, exp-3 with distal outer spine longer 

 than middle outer spine; endopod shorter than exopod; 

 2-segmented, enp-2 as long as enp-1, inner seta implanted at 

 1/3 distance from proximal margin. P2-P4 intercoxal sclerites 

 with few long setules; rami 3-segmented; exp-1 with inner 

 seta; female P2-P3 enp-2 without apophysis at outer distal 

 corner. Armature formula of P1-P4 as follows: 



Exopod 



Endopod 



PI 

 P2 

 P3 



P4 



0.1.023 

 1.1.223 

 1.1.323 

 1.1.323 



1.121 

 1.2.121 

 1.1.121 

 1.1.121 



Female fifth pair of legs not fused medially; exopod and 

 baseoendopod fused to form a bilobate plate; exopodal lobe 

 with 2 spines and 2 setae; endopodal lobe with 2 setae and 3 

 spines, the outer 2 of which are stubby. 

 Male unknown. 



Type species. Bathypsammis longifurca (Bodin, 1968) 

 comb. nov. 



Other species. None. 



Etymology. The generic name is derived from the Greek 

 bathys, meaning deep, and Psammis, probably the most 

 closely related genus known in the Paranannopidae. Gender: 

 feminine. 



Bathypsammis longifurca (Bodin, 1968) comb. nov. 



Synonymy. Psammis longifurca Bodin, 1968. 



Material examined. From Dr Ph. Bodin: holotype dis- 

 sected on 3 slides and now deposited in the collections of The 

 Natural History Museum under reg. no. 1992.1091; Bay of 



69 



Biscay, Stn 308 (46°07' N; 05°00' W), depth 3950 m; coll. 

 August 13 1963, RJVJob-ha-Zelian. 



Bodin's (1968) excellent original description is supple- 

 mented here by the following observations and Figures 

 17-18. 



Antennule 4-segmented, third segment homologous to 

 segments 3-4 in Archisenia. Distal segment with large, swol- 

 len seta anteriorly near proximal corner; as pointed out by 

 Bodin this segment is seemingly subdivided by the raised 

 insertion site of one of the large pectinate spines (Fig. 18A). 

 Armature formula: [1, 8, 14+ae, 16]. 



Mandibular gnathobase (Fig. 17B-C) with 4 long teeth, 

 one trifid, slender element and 1 pinnate seta; a comb of 

 spinules is present at the base of the smaller teeth. The 

 endopod has 1 outer, 1 subapical and 6 apical setae (2 of 

 which are fused basally). 



Maxillule (Fig. 17D). Praecoxal arthrite with 9 spines and 1 

 tubular seta around the inner margin, and 2 geniculate 

 tubular setae on the anterior surface; coxal endite with 4 

 setae, pinnate spine and straight spine with defined flexure 

 zone and small pore near the apex; basal endite with 5 setae. 



Maxilla (Fig. 18B-C) with praecoxal endite drawn out into 

 heavily pectinate spine and bearing 2 articulating elements; 

 coxal endites with 1 serrate spine and 2 setae each. Allobasis 

 with 1 short and 2 long setae; endopod with 4 setae. 



Maxilliped (Fig. 18D). Syncoxa missing in preparation. 

 Basis with naked seta on inner margin, 2 spinular rows on 

 anterior surface and another one on posterior surface; 

 endopodal claw with 2 accessory setae. 



Intercoxal sclerites of P2-P4 U-shaped (as in Fladenia) and 

 provided with few long setules near lateral margins. 



Fifth leg (Fig. 17E) with 2 large tube pores on anterior 

 surface. 



Genital field (Fig. 18E) with minute copulatory pore. The 

 internal structures of the genital double-somite were 

 destroyed during the dissection, so no observations of the 

 copulatory duct and the seminal receptacles could be made. 



Pseudoperculum very weakly developed. Distribution of 

 caudal rami setae as in Fig. 18F-G; seta III dislodged in both 

 rami, insertion site indicated by small socle (Fig. 18G). 



P. longifurca does have certain features in common with P. 

 longisetosa and P. longipes, namely: anterior pair of rostral 

 sensillae enlarged (Fig. 17A); only 1 lateral seta on both rami 

 of the mandible (Fig. 17B); 2 setae on exp-1 of the antenna; 2 

 setae on enp-2 of the P2; and fused rami in the female P5. 

 However, P. longifurca lacks certain important features 

 shared by the other two species, namely: no large strongly 

 pinnate seta on the basis of the maxilliped, the seta on this 

 segment being small and naked (Fig. 18D); the endopod of 

 P2 is not distinctly longer than the exopod; the proximal inner 

 seta of P2 enp-2 is not displaced to the posterior surface; the 

 inner distal seta of P3-P4 enp-3 is not reduced; and, there is 

 no attenuation of the outer distal corner of P2 enp-1. Finally, 

 P. longifurca has a number of characters which are not shared 

 by the other members of this genus such as: (i) a plume of 

 long fine setules at the inner distal corner of the caudal 

 ramus; (ii) an outer basal seta on PI which is nearly as long as 

 the exopod; (iii) a PI endopod which is shorter than the 

 exopod and in which both segments are equal in length; (iv) a 

 P5 with peculiar spines on the endopodal lobe and a minute 

 outer basal seta; (v) a primitive setal formula for the exopods 

 of the swimming legs which is shared only by Archisenia and 

 Jonesiella. On the basis of these characters we assign P. 



