abrupt forward slope. Th4 and Th5 separate. Prosome 

 length 4 times urosome. Genital segment slightly 

 wider than long, protruding ventrally one-third depth 

 of rest of urosome. Caudal rami slightly longer than 

 wide. Inner caudal seta reduced. 



Al exceeding caudal rami by 3-4 segments. 

 Specimen examined lacked segments 24-25; 

 remainder as Table 4. 



Mn B2 with 2 inner setae (Farran, 1908). 



Mxl gnathobase apparently without proximal 

 posterior setae. 



PI (Fig. 166) B2 and Rel outer distal edge with 3-4 

 small teeth. 



P2 (Fig. 167)-P4 damaged on specimen examined; 

 described by Vervoort (1957); P4 (Fig. 168) Bl with 

 inner transverse row of thin setules. 



Atlantic Ocean 



Northeast: Farran (1908, 1926), 360-1,800 m. — 

 Grice and Hulsemann (1965), 250-4,750 m. 



East: Roe (1972a, b), 400-800 m. 



Mediterranean Sea: ?Grice (1971), 1,190-1,350 

 m. 



Northwest: Grice (1963), 620-1,200 m. —Wheel- 

 er (1970), 2,000-4,000 m. 



West: Wheeler (1970), 2,000-4,000 m. 



Caribbean Sea: Park (1970), 208-1,900 m. 

 Antarctic 



Pacific Sector: Vervoort (1957, 1965), 250-500 

 m. 



Indian Sector: Vervoort (1957, 1965), 500-1,000 

 m. 



Male. — Undescribed. Grice and Hulsemann (1965; 

 unpublished station list, 1966) reported a male of M. 

 cuUrifer (1.2 mm). Roe (1972b) reported 1 male (1.14 

 mm). 



Remarks 



Rose's (1933) and Farran and Vervoort's (1951b) 

 descriptions are from Farran (1908); Farran and Ver- 

 voort (1951b) included length data (up to 1.91 mm) 

 from Vervoort (1946) which probably include lengths 

 of M. heronae or another species. The above descrip- 

 tion limits the length of female M. cultrifer to the 

 most probable records. Vervoort (1957) did not in- 

 clude his earlier (1946) record in the description of M. 

 cultrifer. Possibly records of small M. cultrifer (1.0- 

 1.17 mm) by Vervoort (1946) and Grice and 

 Hulsemann (1965; unpublished station list, 1966) are 

 of M. crassus. 



Grice's (1971, fig. 3C) lateral view of M. cuUrifer is 

 not as robust as other descriptions of this species (see 

 M. heronae). Grice did not indicate the lengths of his 

 specimens. 



Distribution 



Minoda's (1971) specimens smaller than 1.70 mm 

 are included in the summary below; the larger 

 specimens are considered M. heronae. 



Pacific Ocean 



North: Minoda (1971), 743-1,230 m. 



Northeast: Davis (1949), 1,100-1,900 m. — Flem- 

 inger ( 1967), 0-140 m. —Present study, 1,300- 

 1,500 m. 



Northwest: Furuhashi (1966), 252-512 m. —Mi- 

 noda (1971), 195-485 m. 



Southwest: Vervoort (1957), 500-750 m. 



Indo-Pacific: Vervoort (1946), 340-1,000 m. 

 Indian Ocean 



West: Grice and Hulsemann (1967), 750-4,000 

 m. 



2. Mimocalanus nudus Farran, 1908 



(Figures 1G9-180) 



Mimocalanus nudus Farran, 1908, p. 24-25, pi. 1, fig. 



1-4. —Farran and Vervoort, 1951b, p. 2-3, fig. 2b-c, 



e-g. 

 Mimocalanus distinctocephalus Brodsky, 1950, p. 



136-137, fig. 56. 



Type Specimens: Syntypes, 2 females (2.30, 2.64 mm), 

 BM 1908.7.6.5. 



Type Locality: Northeast Atlantic, 720-1,440 m. 

 Material Sti'DIED: Syntype, female (2.30 mm), 

 sample 4 (Table 3); 1 female (2.68 mm), sample 35; 2 

 females (2.57. 2.65 mm) and 1 male (2.50 mm), sam- 

 ple 36; 4 females (2.50-2.70 mm, mean = 2.61 mm), 

 sample 37. 



Description 



Pi Ri with 2 inner setae; P2 Ri2 with 1 outer seta; 

 P3-P4 Ri3 with 1 outer seta. 



Female.— Length 2.28-2.70 mm (Figs. 169, 170). 

 Prosome in dorsal view robust ovoid; head somewhat 

 truncate. In lateral view with fairly abrupt forward 

 slope. Th4 and Th5 separate. Prosome length 4 times 

 urosome. Genital segment slightly wider than long, 

 protruding ventrally one-third depth of rest of 

 urosome. Caudal rami length I's times width. Inner 

 caudal seta reduced. 



Al terminal segments missing on all described 

 specimens. Segments 20-25 missing on specimens ex- 

 amined; armature of remaining segments as Table 

 4. 



Mn B2 apparently with 2 inner setae. Blade (Fig. 

 171) with large, sharp, slightly curved ventral tooth 

 followed by 2 large and 1 slender tricuspids, a shorter 

 bicuspid, 3 slender teeth, and a dorsal seta. 



Mxl gnathobase with 1 proximal posterior seta, 

 nearly as large as smallest strong marginal setae; 

 proximal anterior seta also relatively large; distal 



69 



