margin with hairs. P4 Bl proximal inner posterior sur- 

 face with row of long and short setules; inner margin 

 without hairs. 



P4 B2 posterior surface nude or with several thin 

 setules. 



P3-P4 Re2 posterior surface with proximal row of 

 strong, fairly wide spines and distal row of smaller 

 spines. Ri2-3 surface spines shorter than on S. 

 elongatus. 



P2 Re8 with 2 distal rows of spines. P3 ReS with 3 

 evenly spaced rows of spines as on S. elongatus. P4 

 Re3 posterior surface with 3 groups of spines, smaller 

 and fewer than on >S'. elongatus. Outer spines of P2-P4 

 Re2-3 longer than on S. elongatus. 



Re terminal seta with following number of primary 

 teeth: P2 (ca. 25); P3 (21-25); P4 (25-27). 



Male.— Length (1.3?-) 1.5-1.90 mm. Prosome 

 anterior irregular in dorsal view, posterior somewhat 

 rounded; in lateral view with fairly abrupt forward 

 slope. Prosome length 2 '/a times urosome. Caudal 

 rami about as long as wide, symmetrical. Caudal 

 setae symmetrical. 



Al reaching middle of urosome segment 2; segment 

 1 with cluster of short spinules on anterodorsal 

 surface. IV-2s, 2e; VIII-2s, 2e; XV-ls, le; XIX- 

 Is?, le; right XX-damaged; left XX-le; remainder as 

 Table 4. 



Mxp Ri4-5 outer setae reduced; Ri5 inner edge 

 without spinules. 



PI (Fig. 132) similar to that of S. elongatus male ex- 

 cept Rel outer spine shorter, Re2 outer spine larger. 



P2 (Fig. 133) as on female, except no anterior 

 spinules on Re2, other surface spines slightly stronger, 

 Re2 spines in cluster, Re3 with 3 rows of spines, and 

 terminal seta with ca. 45 teeth. 



P3 (Fig. 134) as on female except no anterior 

 spinules on Re2, Re2 with distal cluster of spines, and 

 Re3 terminal seta with ca. 48 teeth. 



P4 (Fig. 135) as on female except Bl without inner 

 seta and without inner transverse row of setules, Re2 

 with distal cluster of spines, Re3 surface spines 

 stronger, and Re3 terminal seta with ca. 54 teeth. 



P5 (Fig. 136) biramus, left-handed. Left Bl 

 reaching one-third length of right B2; left B2 reaching 

 middle of right Rel. Right leg, including terminal 

 blade, longer than left. Right Re longer than left; right 

 Ri longer than left. Order of length, longest to 

 shortest, of Re segments: left 1, 2, 3; right 2, 1 = 3. 

 Left Ri reaching two-thirds length of longest left Re 

 terminal blade. Right Ri reaching about to end of 

 longest right Re terminal blade. Probably each Rel 

 with short seta on outer distal edge. Right Rel-2 more 

 or less fused. Inner edge of left Re2-3 with long hairs. 

 Each Re probably with 1 small and 1 moderate 

 bladelike terminal setae. 



Remarks 



Sars (1901) described a Norwegian Spinocalanus 

 species as S. longicornis, later (1903) adding the male 



and changing the name to S. abyssalis. Sars (1901) 

 neglected to describe the outer seta of P2 Ri2 of his 

 Norwegian specimens; a remounting of his prepara- 

 tion clearly showed this seta (Fig. 128). Sars also 

 failed initially to describe the surface spination of P2- 

 P4 Re on his female specimens. These omissions, and 

 the incomplete descriptions of S. abyssalis 

 Giesbrecht, masked the distinctness of Sars' 

 specimens. Most subsequent workers seemed to follow 

 the authority of Sars, who incorrectly equated the 

 Norwegian species (common in the North Atlantic) 

 with both .S. abyssalis Giesbrecht and S. longicornis 

 Sars, 1900. 



Farran (1926) recognized two size groups in the 

 Northeast Atlantic, the larger representing Sars' 

 Norwegian species. Unfortunately Farran retained the 

 name abyssalis for this group, renaming the smaller 

 forms abyssalis var. pygmaeus (see S. longicornis 

 Sars, 1900). 



Sars' ( 1903) figure of male P5 was poorly printed, 

 the end of left Ri not shown well; therefore, later 

 copies of this figure (Rose, 1933; Brodsky, 1950; 

 Farran and Vervoort, 1951a) failed to show the full 

 length of left Ri. This specimen's appendage has been 

 redrawn in the present study (Fig. 133). 



Van Breemen (1908), Rose (1933), and Farran and 

 Vervoort (1951a) copied some of Sars' figures, 

 although they included figures or descriptions of S. 

 abyssalis Giesbrecht and S. longicornis as well. 



With (1915) included a brief description of male 

 stage V. 



Tanaka (1937) apparently combined one female S. 

 horridus (see above) and one male S. brevicaudatus as 

 S. abyssalis. Brodsky (1950) recognized that neither 

 represented S. abyssalis Giesbrecht, and considered 

 Tanaka's specimens "Spinocalanus sp.?" 



Davis (1949) correctly illustrated S. brevicaudatus 

 P2 Ri2 with 1 outer seta, but failed to note its dis- 

 tinctness from S. abyssalis. 



Grice and Hulsemann (1965) gave a lateral view of 

 the female S. brevicaudatus; their unpublished sta- 

 tion list (1966) indicated a size of 1.4-2.0 mm (female) 

 and 1.3 mm (male). This small male might be S. 

 longicornis, and the length is questioned in the size 

 range of males given above. 



Esterly (1906) very briefly, and without il- 

 lustrations, described a single female as a new species, 

 S. major. There is nothing in Esterly's description 

 that sets S. major apart from S. abyssalis, except S. 

 major's larger size. A. Fleminger examined the Ester- 

 ly Collection and located a single slide which was 

 labeled "Spinocalanus." This slide, now deposited in 

 the U.S. National Museum (USNM 143692), con- 

 tained only A2, Mxl, and Mxp, which appeared con- 

 sistent with those appendages of S. brevicaudatus. 

 However, the lack of PI and P2 makes this identifica- 

 tion uncertain. Spinocalanus brevicaudatus is known 

 from the area in which Esterly found S. major; his 

 brief description is consistent with that of S. 

 brevicaudatus, which is considered in the present 



55 



