986 



MR A. PRINGLE JAMESON ON THE 



Horizontal distribution : 36° 5' N., 30° 50' W.-34° 43' S., 17° 15' E. 



Vertical distribution : surface. 



Temperature range : 61-3°-81-5° F. 



Stations: 7, 8, 13, 17, 18, 20, 21, 22, 25, 26, 27, 28, 30, 31, 35, 37, 38, 39, 41, 

 42, 44, 47, 49, 59, 65, 66, 69, 70, 72, 82, 85, 86, 87, 90, 91, 93, 94, 95, 476, 477, 

 498, 501, 502, 506, 510, 511, 515, 522, 524, 525, 526, 529, 533, 540. 



Sagitta robusta (Doncaster). 



Considerable difficulty was experienced in identifying this species, and even yet 

 the results do not seem to be quite satisfactory, for young forms of Sagitta robusta 

 are rather liable to be confused with Sagitta bipunctata. on account of a certain 

 correspondence between the tail-percentages and the numbers of the jaws and teeth 

 of these two species. This confusion, of course, does not arise when the specimens are 

 in good order, and when all the features are clearly seen ; but damaged and strongly 

 contracted specimens of S. robusta are frequently very like S. bipunctata, and require 

 some care in determination. The features on which I have relied for the identifica- 

 tion of this species have been the small number of the jaws, never more than seven 

 — Ritter-Zahony (1911) in his monograph admits species with eight jaws, but under 

 the circumstances I have thought it best to fix seven as the typical number ; the 

 presence of a distinct collarette ; and an opaque body, all the parts of which, including 

 the teeth and the jaws, are of a stout build. An important feature would seem to be 

 the position of the seminal vesicles near or touching the posterior fins, but unfortunately 

 seminal vesicles were not observed in any of the specimens. 



Length. 



Tail- 

 percentage. 



Jaws. 



Aut. Teeth. 



Post. Teeth. 



1 14 

 1.3 -5 

 12 

 11 



8 



? 



26 

 25 



27 

 28 



7 

 7 



7 

 7 

 7 



8 

 7 

 6 or 7 

 7 

 6 



12 

 ? 10 

 12 

 12 

 13 



Horizontal distribution : 32° 11' N., 34° 10' W.-23° 8' S., 39° 40' W. 

 - Vertical distribution : surface. 



Temperature range : 74°-8r5° F. 



Stations : 15, 18, 19, 26, 29, 33, 39, 60, 73, 85, 526, 538. 



It may be noted that S. robusta is said to have a smaller temperature range than 

 S. bipunctata, or at all events that it does not range so far to the north and south. 

 So far as my results go they bear out this statement. 



