70 



Definitive observatinns: 

 Neritic. 

 Surface. 

 Temperature : c. 28° to 29° C. 



Sagitta furcata Steinhaus (Charts I, II). 



L o c a 1 i t i e s : 



\. temperate and tropical Atlantic, and Mediterranean. 

 Definitive observations: 



Oceanic (and Messina). 



N. limit: 5i°5SN., io°2o'\V. at 1 1° C. 



S. limit: 7°33'S., 2o°i9'\V. 



Surface at 17° C. 



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



Deepcst 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 i 1° C. 



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

 few specimens in the u])per mesoplankton at my Biscayan stations, and was shown h\ tlie 

 closing nets of the National at stations vet further south to extend vet more deeply inlo 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 trulv 

 oceanic records at present impossible. 



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

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

 describer, Dr. .Stkinh.'\us, 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). 



L o c a 1 i t i e s : 



Karajak-fiord in Groenland; 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'\V. (Humboldt's Currentt: Japan. 



Definitive observations: 

 Oceanic and neritic. 

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

 Surface; in the Siboga area at 2S° 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 thal hexaptera is very nearly what bipimctata is alleged 

 to be. Hut Jtexaptcra is much niurc of an oceanic form (rarely neritic), stenohaline, eurybathic, 

 and eurythermal; it a|)pcars lo be nearly cosmopolitan, but though eurythermal within wide limits 

 it does not seem to e.vtend into the mesoplankton to the same depths as do some other species'). 



I) Sincc ünishiog the Sil>0(;.T coUection, 1 have foiiiul this species among ihc Chaetognalh.i taken at the Winter Oiiaiters of 

 the ^I >iscovery'. This praclically conipletL's its record as a cn>nu>pL)litan species. 



