96 



L. BOUCK, D. THISTLE AND R. HUYS 



as long as exp-1, with short, slender inner seta distally and outer 

 margin spinular rows extending to insertion of subdistal pinnate 

 seta; exp-3 vestigial, largely incorporated into exp-2, with 2 genicu- 

 late spines and 2 claws. Endopod 2-segmented; enp-1 elongate, with 

 outer spinular rows extending to anterior face; enp-2 0.3 times as 

 long as enp-1, with spinular row and bearing geniculate spine, claw, 

 and short, slender inner seta distally. 



P2-P4 (Figs 15A-B, 16B) with 3-segmented exopods and 

 endopods 3-segmented in P2 and P3 and 2-segmented in P4 with the 

 distal segment comprised of two fused segments; indentation at 

 outer lateral margin marks the plane of fusion. Coxae with spinular 

 rows at outer distal corner (P2-P4) and posteriorly near outer edge 

 of P2 and P4. Bases with outer bipinnate spine (P2) or naked seta 

 (P3-P4), and spinules plus a pore at outer distal corner. Endopods 

 distinctly shorter than exopods. Spinular rows present on posterior 

 surface of P3-P4 exp-3, P4 exp-1 and -2, P2-P4 terminal endopodal 

 segments. Outer distal spine of P2-P4 exp-3 tripinnate. Pores present 

 as illustrated (Figs 15A-B, 16B). Seta and spine formula of P2-P4 

 as in Table 1 . 



P5 (Fig. 15D) biramous, not fused medially. Baseoendopod with 

 numerous anterior surface and marginal spinular rows; endopodal 

 lobe triangular, with 5 bipinnate setae, outermost seta with flagellate 

 tip; outer basal seta slender and arising from cylindrical process. 

 Exopod 1.1 times as long as wide (excluding distal spines) with 

 numerous anterior, posterior and marginal spinular rows, with 1 

 inner, 1 apical and 3 outer bipinnate spines, apical, inner, and distal 

 outer ones with flagellate tips; posterior surface with pore. 



Genital double somite (Figs 16A,C) wider than long. Genital field 

 located far anteriorly. Copulatory pore large, midventral; leading via 

 short copulatory duct to single median seminal receptacle. Gonopores 

 paired, closed off by opercula derived from vestigial sixth legs 

 bearing 3 naked setae. 



MALE. Body length: measured from anterior margin of rostrum to 

 posterior margin of caudal rami : 4 1 1 |im (x = 398 p.m, n = 4) ; without 

 rostrum and caudal rami: 367 urn (x = 362 urn, n = 4). Body width: 

 1 89 urn (x = 1 87 urn, n = 4). Not all sensillae shown in habitus views 

 (Figs 17A-B). Sexual dimorphism in body size, rostrum (Fig. 17D), 

 antennule, P2 endopod and exp-3, P3 enp-3 and exp-3, P5, P6, and 

 urosome segmentation (Figs 18B-C). 



Antennule (Fig. 18 A) 6-segmented, chirocer ae-bearing segment 

 not conspicuously swollen; segments 3 and 5 longest; with 

 geniculation between segments 5 and 6. First segment with several 

 spinular rows along anterior margin; fifth segment with an aesthetasc 

 (40 urn long), 3 modified elements, and anterior distal corner 

 produced into blunt apophysis; with armature formula 1-[1], 2-[l], 

 3-[8 + 1 unipinnate], 4-[9], 5-[9 + (1 + ae) + 3 modified], 6-[5 + 

 acrothek]. 



P2 (Fig. 17C) as in 9 except for endopod and exp-3. Enp-1 with 2 

 outer rows of spinules. Enp-2 with outer distal corner produced into 

 apophysis, extending one half the length of enp-3; outer margin 

 spinulose; inner margin with subdistal bipinnate seta. Enp-3 with 

 spinulose outer margin, short distally pinnate outer spine, long 

 bipinnate spine distally, and 1 bipinnate inner seta; with spinules at 

 base of distal bipinnate spine. Exp-3 without posterior spinules 

 found in 9 . Pores present as illustrated (Fig. 17C). 



P3 enp-3 and exp-3 without posterior spinules found in 9 . 



P5 (Fig. 18D) biramous. Baseoendopods fused medially forming 

 transversely elongate plate; endopodal lobe slightly developed, with 1 

 outer, pinnate seta and 1 inner, bipinnate seta; outer basal seta slender, 

 arising from cylindrical process; with spinules around articulation 

 with exopods. Exopod as in 9 except for an additional bipinnate seta 

 along the outer margin, fewer spinular rows, and more pores. 



P6 (Fig. 1 8C) symmetrical; with distal seta; located more laterally 

 than in the 9 . 



ETYMOLOGY. Named for Dr. Eric Shulenberger, an administrator 

 of scientific research who believed in the importance of taxonomy 

 enough to fund some. 



Notes. 



N. shulenbergeri sp. nov. and the three Brazilian species (Jakobi, 

 1954) share the presence of only 1 inner seta on P2 enp-3. Species 

 within this group are closely related and identification is best 

 achieved by paying particular attention to the PI endopod and the P5 

 in both sexes. The sexually dimorphic spinule rows on the posterior 

 face of P2 exp-3 and P3 exp-3 and enp-3 are unique for this species 

 but might well have been overlooked in some other congeners. 



Genus Mucropedia gen. nov. 



Diagnosis . Harpacticidae. Antennule 9 8-segmented, without pin- 

 nate or plumose setae on segments 1-6; without strong, modified 

 spines on segments 3-5 or enlarged pectinate or pinnate spines on 

 segment 6. Antennulecfwithout modified spines on segment 3. 

 Antennary exopod 2-segmented, with armature formula [2, 2]. 

 Maxilla with 4 spines/setae on praecoxal endite. P2-P3 endopods 3- 

 segmented, P4 endopod 2- or 3-segmented. P2 9 enp-3 with 2 inner 

 setae. P3 9 enp-2 without inner seta. P4 exp-3 with 2 outer spines 

 in 9 and 3 outer spines incf . P4 enp-3 (or enp-2 when 2-segmented) 

 with 2 inner setae in both sexes. P2d"enp-2 without distinct apophy- 

 sis, inner seta modified into stout spine; enp-3 with 1 apical seta 

 ( inner one lost), outer spine fused to segment. P3 cf enp-2 outer distal 

 corner attenuated. 



Swimming leg setal formula: 





exopod 



endopod 



P2 



0.1.223 



0.1.221 [9] 

 0.1.211 [Cf] 



P3 



0.1.323 



1.0.221 



P4 



0.1.322 [9] 

 0.1.323 [cf] 



1.0.221 or 1.221 



P5 exopod elongate-oval in both sexes. P5 endopodal lobe 9 not 

 developed; distalmost inner seta rudimentary. 



Sexual dimorphism in rostrum, antennule, P2 endopod, P3 

 endopod, P4 exopod, P5, P6, genital segmentation and size. 



TYPE SPECIES. Mucropedia cookorum gen. et sp. nov. 



Other species. M. kirstenae sp. nov. 



ETYMOLOGY. The generic name is derived from the Latin mucro, 

 meaning sharp point, and pes, meaning foot, and refers to the 

 apophysis present on P3 enp-2 in the male. Gender: feminine. 



Mucropedia cookorum sp. nov. 



Type LOCALITY. Gulf of Mexico: 29°40.63'N, 84°22.80'W, north- 

 ern Gulf of Mexico, 18m depth, unvegetated medium sand; see 

 Thistle et al. (1995) for additional description. 



Material examined. 



The Natural History Museum: holotype9in alcohol (BMNH 

 1999. 199); allotypic paratypecf in alcohol (BMNH 1999.200); other 

 paratypes are 29 9 and lcTin ethanol (BMNH 1999.201-203) and 

 29 9 and 2d"cfon slides (BMNH 1999.204-207). 



