152 



S. OHTSUKA, G.A. BOXSHALL AND H.S.J. ROE 



posterior surface); both endopods 1-segmented, lobate. Right 

 exopod (Fig. 32H-J): second and third segments almost 

 completely fused to form lamelliform compound segment, 

 tapering distally; inner medial triangular process with 2 

 minute spinules (Fig. 321) at tip; 1 subterminal outer and 1 

 terminal setule present (Fig. 32J); muscles between second 

 and third segments present, but less developed than in 

 Paraugaptiloid.es . Left exopod similar to that of male P. 

 similis. 



Remarks. Deevey (1973) first discovered sexual dimor- 

 phism in the mandibular palp of this species, but overlooked 

 the vestigial seta on the first exopodal segment of the female. 

 P. buchani shows no sexual dimorphism in setation of the 

 antennary endopod and exopod, unlike P. bermudensis 

 (Deevey, 1973) and P. similis (A. Scott, 1909; present study). 

 Unfortunately the only female of P. buchani lacked the 

 terminal segments of the right antennule. The posterior setae 

 on segments XXV and XXVI of the left antennule are 

 ornamented with thick setules as in the right antennule of 

 female P. similis. In P. buchani the asymmetrical pattern in 

 antennulary armature elements may be different from that of 

 P. similis. 



Genus Scutogerulus Bradford, 1969 



Diagnosis (emended). Only female known. Body relatively 

 large, more than 3 mm long. Cephalosome separate from first 

 pedigerous somite; urosome about one-third as long as 

 prosome. Genital double-somite as long as wide; gonopore 

 and copulatory pore sharing common slit-like aperture, 

 gonopore located anteriorly, copulatory pore at innermost 

 corner of the slit; copulatory duct swollen anteriorly; seminal 

 receptacle relatively small and simple in shape. Caudal rami 

 slightly asymmetrical, left caudal ramus longer than right, 

 longer than wide, with setae II and III relatively long. 



Antennules symmetrical, reaching almost to end of 

 prosome, 22-segmented; posterior margin of proximal seg- 

 ments bearing long setules from segment I to XIII; segment 

 III separate from IV; segment IV without aesthetasc; seg- 

 ment XIII with 2 setae; segment XXIII separate from XXIV. 

 Antenna: first endopod segment without inner seta; second 

 endopod segment with 3 medial and 5 terminal setae; exopod 

 indistinctly 8-segmented. Mandibular palp: endopod rudi- 

 mentary, 1-segmented, with 2 setae; seta on first exopod 

 segment not reduced; outer seta on fifth segment relatively 

 long. Maxillule: praecoxal arthrite with 4 finely serrate spines 

 and 1 process; coxal epipodite with 6 setae; coxal endite 

 carrying 1 long seta; endopod having single seta. Maxilla: first 

 praecoxal endite with 1 relatively well developed seta and 1 

 vestigial element; second praecoxal endite with 1 seta; basal 

 spine with 3 rows of minute spinules; setae on endopod with 

 row of triangular spinules. Setal formula of endopod of 

 maxilliped: 1,4,4,3,3,4; setae a and b on sixth endopod 

 segment vestigial. 



Third exopod segment of leg 1 with outer medial tuft of 

 short setules and subterminal outer spine. Leg 5 biramous, 

 carrying 1-segmented rudimentary endopod with 1 terminal 

 seta and 2-segmented exopod with 1 outer spine on first 

 segment and 2 terminal setae on second segment. 



TYPE SPECIES. Scutogerulus pelophilus Bradford, 1969 

 (monotypic). 



Remarks. The new genus Campaneria is established for the 

 paratypic male of S. pelophilus. 



Ecological note. Bradford (1969) suggested that S. pelo- 

 philus is a deep-sea hyperbenthic species. However, Cam- 

 paner (1984) considered that it was less associated with the 

 bottom than members of his second group, namely, Parami- 

 sophria, Rhapidophorus and some species of Metacalanus, 

 since S. pelophilus has well-developed antennules and anten- 

 nae for swimming. The presence of long caudal setae also 

 supports Campaner's (1984) inference. 



Scutogerulus pelophilus Bradford, 1969 (Figs 33,34) 



Material examined. $, Paratype, New Zealand Oceano- 

 graphic Institute, p-121. 



Body length. 3.6 mm (after Bradford, 1969). 



Description. Female. Cephalosome separate from first 

 pedigerous somite. Urosome (Fig. 33A) slender. Genital 

 double-somite (Fig. 33B,C) as long as wide; paired gonop- 

 ores and copulatory pores symmetrically arranged; gonopore 

 sharing common slit-like aperture with copulatory pore; 

 gonopore located anteriorly in slit, genital operculum accom- 

 panied by muscles; copulatory pore small, located at inner- 

 most corner of slit; copulatory duct swollen anteriorly, 

 relatively short; seminal receptacle simple in shape, pea-like; 

 receptacle duct short, opening beneath gonopore. Left caudal 

 ramus slightly longer than right, with seta V longer than 

 urosome (Fig. 33A). 



Antennule (Fig. 33D-F): eighth (X) to 10th (XII) segments 

 separate; 12th (XIV) and 13th (XV) segments partly fused 

 (Fig. 33D). Fusion pattern and armature elements as follows: 

 I-III-7 + 2 aesthetascs, IV-2, V-2 + aesthetasc, VI-2 + 

 (small) aesthetasc, VII-2 + aesthetasc, VIII-2 + (small) 

 aesthetasc, IX-2 + aesthetasc, X-2 + (small) aesthetasc, 

 XI-2 + aesthetasc, XII-2 + (small) aesthetasc, XIII-2 + 

 aesthetasc, XIV-2 + aesthetasc, XV-XVI-4 + 2 aesthetasc, 

 XVII-2 + aesthetasc, XVIII-2 + aesthetasc, XIX-2 + 

 aesthetasc, XX-2 + aesthetasc, XXI-2 + aesthetasc, 

 XXII-1, XXIII-1, XXIV-XXV-4 + aesthetasc, XXVI- 

 XXVIII-8 + aesthetasc. First to 11th (XIII) segments fringed 

 with long setules along posterior margin. 



Antenna: first endopod segment without inner seta, second 

 segment carrying 3 inner setae and 5 terminal setae; exopod 

 (Fig. 33G) indistinctly 8-segmented, setal formula 

 0,1,1,1,1,1,0,3. Mandibular gnathobase missing, probably 

 lost during dissection. Mandibular palp (Fig. 33H): endopod 

 rudimentary, 1-segmented, bearing 2 setae of unequal 

 lengths; seta on first exopod segment not reduced, fifth 

 segment with 2 setae, one of which shorter but not reduced. 



Maxillule: praecoxal arthrite (Fig. 34A) with 4 spinulose 

 spines and 1 process along inner margin and row of long 

 setules on surface; coxal endite with well-developed spinulose 

 seta; coxal epipodite with 6 setae (only 4 setae and 2 scars 

 remaining on slide); basal seta short, endopod rudimentary, 

 1-segmented, with 1 short seta terminally (Fig. 34B). Maxilla 

 (Fig. 34C): first praecoxal endite with spinulose seta and 1 

 vestigial element, second endite with bilaterally spinulose 

 seta. Maxilliped: innermost seta on fourth and fifth endopod 

 segments (Fig. 34E, indicated by arrowhead) not reduced; 

 sixth endopod segment (Fig. 34F) bearing stout, elongate 

 setae c and d with row of triangular spinules and reduced 

 setae a and b. 



