Al reaching anal segment. 



Mxp Bl apparently without transverse spine-comb. 



P4 Bl reported by Sars (1925) to lack transverse row 

 of spinules on inner posterior surface; row of spinules 

 reported by Wolfenden (1911). 



Male.— Adult unknown. [Owre and Foyo (1967) 

 briefly described one male stage V (size not reported). 

 Urosome was reported with 5 segments, which would 

 indicate an adult specimen, but the illustrated P5 

 suggest stage V male. The crest and rostrum were as 

 on adult female.] 



Remarks 



Sars (1907) originally reported female M. tenera 

 length as 2.20 mm; apparently this was an error, cor- 

 rected to 2.30 mm (Sars, 1925; Belloc, 1960). 



The descriptions by Rose (1933) and Farran and 

 Vervoort (1951b) are from Sars (1924, 1925). 



Distribution 



Indian Ocean 

 Northwest: Sewell (1929), 1,260 m. 

 West: Grice and Hulsemann (1967), 1,000- 



2,000 m. 

 Southwest: De Decker and Mombeck (1965), 



1,000-1,500 m. 

 Atlantic Ocean 



Northeast: Farran (1926), 900-3,600 m. 

 East: Grice and Hulsemann (1965), 1,000-2,800 



m. 

 Central: Sars (1907; 1924, 1925), 0-3,000 m. — 



Wolfenden (1911). —Wheeler (1970), 2,000- 



4,000 m. 

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

 Caribbean Sea: Owre and Foyo (1964, 1967), 



877-1,500 m. —Park (1970), 203-1,900 m. 



(3. Oxycalanus spinifer Farran, 1908) 



See Monacilla typica Sars, 1905. 



(4. Oxycalanus semispinus Scott, 1909) 



See Monacilla typica Sars, 1905. 



(5. Monacilla dubia Scott, 1909) 



See Monacilla typica Sars, 1905. 



(6. Hypsicalanus gracilis Wolfenden, 1911) 



See Monacilla tenera Sars, 1907. 



7. Monacilla gracilis (Wolfenden, 1911) 



Oxycalanus gracilis Wolfenden, 1911, p. 221-222, fig. 



10; pi. 25, fig. 12-14. 

 Monacilla gracilis. — Tanaka, 1956, p. 398-399, fig. 



20. 



Type SPECIMEN: Unknown. 



Type Locality; Central Atlantic, 0-3,000 m. 



Description 



Female. — Length 1.8-2.25 mm. Similar to Mona- 

 cilla typica, except genital segment symmetrical, and 

 transverse row of long spinules on inner posterior sur- 

 face of P4 Bl equal length left and right, reaching 

 beyond distal edge of Bl. 



Male. — Unknown. 



Remarks 



M. gracilis had been considered a synonym of M. 

 typica. Tanaka (1956) reported one specimen which 

 he considered M. gracilis, a distinct species. Vervoort 

 (1963) pointed out that Tanaka's specimen may be 

 distinct, but that it can only be referred to 

 Wolfenden's M. gracilis with some reservations. 



Distribution 



Pacific Ocean 



Northwest: Tanaka (1953, 1956), 0-1,000 m. 

 Atlantic Ocean 



Central: Wolfenden (1911), 0-3,000 m. 



(8. Monacilla typica var. asymmetrica 

 Tanaka, 1956) 



(M. typica var. asymmetrica Tanaka, 

 1953, nomen nudum) 



See Monacilla typica Sars, 1905. 



9. Monacilla sp. 



Monacilla typica. —Wheeler, 1970, p. 9, fig. 21-22. 

 Not M. typica Sars, 1905. 



Remarks 



Wheeler (1970) reported one male (1.01 mm) as M. 

 typica. P5 were damaged, but apparently differed 

 from M. typica P5. This specimen, as well as other 

 small Monacilla males, should be reexamined. Ver- 

 voort (1946) reported one male (also 1.01 mm) as M. 

 typica; it may be the same species as Wheelpr's 

 specimen. No females can at present be assigned to 

 this species. 



66 



