994 DR. G. HERB BUT FOWLER ON THE [Dec. 15, 



more recent figure of Strodtmann *, owing doubtless to ill-preserved 

 material, are capable of improvement in respect of the lateral fins. 

 There can be no doubt that the ' Research ' specimens are refer- 

 able to this species, since they agree with Mobius's description 

 and figures of the cephalic armature to the minutest detail. 



This species appears to be an essentially northern form. It was 

 originally described by Mobius from the following localities : 

 N. of Hanstholmen, Korsfjord (twice), and N.W. of Skagen 

 (misprinted S.W., loc. cit. p. 158) during the cruise of the 

 ' Pommerania,' 1872. 



It was recorded by Levinsen 2 from Greenland (Kronprinsens 

 Eiland), from 30 m. W. of Cape Farewell, and from lat. 59 N., 

 long. ? ; lat. 57 50' N., long. 48 43' W. ; lat. 57 48' N., 

 long. 43 45' W. 



Strodtmann records it from the North Atlantic Drift (" Gulf- 

 stream "), Irminger (Greenland) Sea, and the Labrador Current, 

 i. e. from 60 to 50 N. latitude, as having failed in no single haul 

 made by the 'National' (Plankton Expedition) in 1889. 



In the Faeroe Channel it was rarely absent from a tow-net. 



The deepest haul in which I obtained this species was in the 

 warm area Sta. 19 , 480 to 350 fathoms ; temperature 46 to 

 47 F. It may be regarded as having a fairly wide range of tem- 

 perature (eury thermal), since it was obtained from the surface at 

 a temperature of 53 F. (haul 15 6), and at a temperature of less 

 than 33 F. (haul 13 #, 31 to 33 F.) in the cold area. 



These four instances are, I believe, the only records of the 

 occurrence of the species. 



In illustration of the ease with which one may fail to collect 

 specimens of a fairly plentiful species, may be cited two successive 

 hauls, made within an hour of each other : 



Haul 19 a, 480 to 350 fm., gave 6 specimens of S. hamata. 

 19 6, 480 to 



In other words, 6 were caught in towing through 130 fm. of 

 water, none in towing through 480 fm. (cf. Strodtmann, loc. cit. 

 p. 367) with the same net at the same place. 



SALPA ASTMMETEIOA, sp. n. (Plate L. figs. 5-8.) 



As was the case with most Salpso collected on the ' Research/ 

 the specimens of this species were considerably damaged by 

 pressure against the tow-net, owing to the heavy rolling of the 

 ship when heaved to. Not all anatomical details could therefore 

 be satisfactorily made out, but the following appear to be good 

 characters : 



EXTERNAL CHARACTERS. Body ovoid, flattened, devoid of pro- 

 cesses. Apertures in solitary form terminal ; apertures in sexual 



1 " Systematik der Chaetognathen," Arch. Naturgeschichte, Iviii. Bd. i. 

 pi. rvii. fig. 17. 



2 " Om nogle pelagiske Annulata," Vidensk. Selsk. Skriften, (6) iii. 321. 



