closely related forms differing in body type; Brodsky 

 suggested that these might be subspecies. 



Tanaka (1956) was the first to recognize, and 

 provide descriptive information on, the male of S\ 

 magnus. 



Sars (1907) reported 5. magnus from the Atlantic 

 and also briefly described a new species, S. latifrons, 

 which he later (1924, 1925) equated with S. magnus. 



Rose (1937) described in detail a new species, S. 

 heterocaudatus. from the Bay of Algiers. He seems to 

 have had but one specimen, although the number was 

 not stated. He agreed that it was close to S. magnus, 

 with essentially only four differences: S. 

 heterocaudatus was characterized by (1) 5 setae on PI 

 Ri, (2) left caudal ramus with an extraordinarily long 

 and thick second from inner terminal seta, (3) 

 symmetrical (sic) caudal rami, and (4) Th5 lateral 

 corners prolonged to nearly the end of genital seg- 

 ment. There is no doubt that S. magnus has 5 setae on 

 PI Ri, and it also has an enlarged left caudal seta; 

 both of these characteristics were described by Farran 

 (1905) and agree with the present material. The 

 caudal rami might be variable in symmetry (see S. 

 similis). The Th5 prolongation is definitely variable, 

 due in part to the contraction of the urosome, 

 although not to the degree shown by Rose; the viewing 

 angle may make the prolongation appear more or less 

 than it is, although Rose's lateral view also indicates a 

 great prolongation. This specimen may have been ab- 

 normal, as suggested by Grice (1971). Nearly 1 yr after 

 collecting S. heterocaudatus, Rose found S. magnus 

 at the same locality, but S. heterocaudatus was never 

 again reported. Rose (1942) described a specimen as 

 the male of S\ heterocaudatus, also from the Bay of 

 Algiers; that this specimen is definitely not in Spino- 

 calanidae has been mentioned by Vervoort (1946). 



Mori (1942) described a female stage V S. magnus 

 as the adult of a new species, S. pacificus. He was 

 aware of the close relationship of the two species, but 

 incorrectly considered S. magnus to have 4 setae on 

 PI Ri, not 5 as did his specimen. Mori's figures essen- 

 tially agree with female stage V examined in this 

 study: PI Ri lobe anterior spinules longer than shown 

 by Mori, extending beyond lobe; P2 as shown by Mori 

 with 1 row of spines on Re2-3 and Ri2; P3 with 1 row of 

 spines on Re2-3 and Ri2-3; P4 with 1 row of spines on 

 Re2 and Ri2-3, and no posterior surface spines on Re3. 

 Re3 on P2-P4 proportionally shorter and wider than 

 on adult females. Mori's specimen was 1.9 mm; it was 

 collected near Palao, "accurate positions unknown." 



Brodsky (1950) described a female (see S. horridus) 

 and a male as a new species, S. spinipes. The descrip- 

 tion of the male is consistent with that of S. magnus, 

 except for a shorter, probably left, P5 Ri, which may 

 have been broken. There are only four species of 

 Spinocalanus known, including S. magnus, with male 

 anal segment not reduced; Brodsky's figure clearly in- 

 dicates a short, nonreduced anal segment. The body 

 form and size is unlike S. validus male; S. antarcticus 

 and i'. angusticeps males have uniramus P5. 



Distribution 



Except for Arctic records and some records in tran- 

 sition areas, between the Atlantic and the Arctic, and 

 around the Antarctic, records of S. magnus are 

 accepted. Spinocalanus magnus is very widespread, 

 horizontally and vertically: 



Pacific Ocean 

 North: Brodsky (1950, 1957), 400-4,000 m. 



— Minoda (1971), 1,000-2,000 m. 

 Northeast: Davis (1949), 1,100-2,300 m. — Flem- 



inger (1967), 0-140 m. 

 East: Present study, 0-3(X) m. 

 Central: Wilson (1942), 50-100 m. —Present study, 



0-1,000 m. 

 Northwest: Brodsky (1950; 1952a, b; 1957), 0- 



4,000 m. —Tanaka (1953, 1956), 0-1,000 m. 



— Furuhashi (1961, 1966), 298-3,010 m. 

 West: Mori (1942). 



Indo-Pacific: Vervoort (1946), 345-2,500 m. 

 Indian Ocean 



North: Sewell (1929), 0-360 m. 



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



4,000 m. 

 Southwest: De Decker and Mombeck (1965), 



1,000-1,500 m. 

 Atlantic Ocean 



North: Lysholm and Nordgaard (1921, 1945), 



400-1,250 m. 

 Northeast: Wolfenden (1904, 1906), 540-1,800 m. 



—Farran (1905, 1908, 1920, 1926), 0-3,600 m. 



—Sars (1912; 1924, 1925), 0-3,000 m. —With 



(1915), 0-1,000 m. — Lvsholm and Nordgaard 



(1945), 300-1,000 m. 

 East: Lysholm and Nordgaard (1945), 1,200- 



3,400 m. -Grice and Hulsemann (1965), 180- 



5,000 m. —Roe (1972b), 550-960 m. 

 Mediterranean Sea: Wolfenden (1906), 0-650 m. 

 —Sars (1907; 1924, 1925), 0-2,300 m. —Rose 



(1937), 0-400 m. — Scotto di Carlo (1968), be- 

 low 300 m. — Hure and Scotto di Carlo (1968), 



below 300 m. —Grice (1971), 850-1,400 m. 

 Southeast: Unteruberbacher (1964), 0-300 m. 

 West: Grice (1963), 600-1,200 m. —Wheeler 



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

 Caribbean Sea: Park (1970), 500-1,900 m. 

 Antarctic 



Indian Sector: Wolfenden (1906, 1911), 0- 



3,400 m. 



The records of Pearson (1906) and Massuti (1939) 

 are previous records of Farran and Sars. 



Probably S. magnus enters the Arctic from the 

 Atlantic, but its distribution there should be in- 

 vestigated further, since the similar S. antarcticus is 

 present over a large part of the Arctic. Reports of S. 

 magnus from the Greenland Sea (Damas and 

 Koefoed, 1907; repeated by Jespersen, 1939b), 100- 

 1,350 m; Davis Strait (Stormer, 1929), 100-300 m; 



29 



