Definitive observations: 

 Neritic. 

 Surface. 

 Temperature : c. 28 to 29 C. 



Sagitta furcata Steinhaus (Charts I, II). 



Localities: 



N. temperate and tropical Atlantic, and Mediterranean. 

 Definitive observations: 

 Oceanic (and Messina). 

 N. limit: 5i°55'N., io°2o'\V. at n° C. 

 S. limit: 7 33' S., 20 19' W. 

 Surface at 17° C. 



Deepest haul (National); 1000 to 800 m. at 8°4 to ii°C, under surface water of M.A. 22°C. 

 Deepest haul (Research); 365 to 182 m. at ii°5C under surface water of 17 to 18 C. 

 Highest temperature, 17° C. 

 Lowest temperature, between 8°4 and 1 1° C. 



This species which is epiplanktonic at Valentia, was found to be also represented by a 

 few specimens in the upper mesoplankton at my Biscayan stations, and was shown by the 

 closing nets of the National at stations yet further south to extend yet more deeply into the 

 mesoplankton. Here, as in other cases, the curious conditions well known at Messina, which 

 bring up deep water species to or near to the surface render a comparison with the truly 

 oceanic records at present impossible. 



The species has at present quite restricted limits, of horizontal and vertical range as 

 well as of temperature: these will probably prove to be valid in the future also, as its original 

 describer, Dr. Steinhaus, was dealing at the same time with large collections from other waters 

 in which it was not represented. 



Sagitta hexaptera d'Orbigny. (Charts IV— VI). 



Localities: 



Karajak-fiord in Greenland; Spitsbergen; Atlantic from 6o°i2'N. to 42°53'S.; Indo-Australian 

 from 40°4'S. to io°N. and I35°E.; S.E. Pacific at 40 S., 79°4o'W. (Humboldt's Current); Japan. 



Definitive observations: 

 Oceanic and neritic. 

 Surface; 70°3o'N., 50 30' W. at 6° C. 

 Surface; in the Siboga area at 28 to 29 C. 

 Deepest haul; 1828 to 1371 m. at 5 5 to 8° C. 

 Highest temperature; 29 C. 

 Lowest temperature; 6° C. 



There seems to be little doubt that licxaptcra is very nearly what bipunctata is alleged 

 to be. But licxaptcra is much more of an oceanic form (rarely neritic), stenohaline, eurybathic, 

 and eurythermal ; it appears to be nearly cosmopolitan, but though eurythermal within wide limits 

 it does not seem to extend into the mesoplankton to the same depths as do some other species 1 ). 



1 J Since finishing the Siboga collection, 1 have found this species among the Chaetognatha taken at the Winter Quarters of 

 the 'Discovery'. This practically completes its record as a cosmopolitan species. 



