74 



The distribution of this much-discussed species, sketched in the Biscayan Report (p. 77) 

 and now enlarged by the Siboga captures, re(}uires no further comment at present. 



The table opposite embodies the definitive observations relative to the depth-distribution of 

 ha?nata, arranged by latitude (the temperatures being added) : its epiplanktonic distribution towards 

 both poles, and mesoplanktonic distribution in tropical regions may thus be readily grasped '). 



Krohnia pacifica Aida. 



L oca 1 i t i es : 



Malay (Siboga area) and Maldive Archipelagos: Japan. 



Definitive observations: 



Neritic. 

 Surface. 

 Temperature: 28° to 29°, and M.A. 21° C. 



Krohnia subtilis Grassi. (Charts I to III). 



Locali tics : 



Temperate (N. and S.) and tropical Atlantic; Mediterranean. Temperate and tropical Indo- 

 Australian. 



D e f i n i t i ve observations. 

 Neritic and oceanic. 



N. limit (Atlantic): 6o°i2'N., 22°56'\V. 

 S. limit (Atlantic): 25° 39' S., 36°5i'W. 

 S. limit (Indo-Australian) 29°3o'S., 42° 50' E. 

 Surface and mesoplankton. 

 IJcepest haul : 850 to 650 m. 

 Highest temperature: 30° 8 C. 

 Lowest temperature: 5° 3 to 5° 8. 



The recorded temperature range is so wide as to suggest that this species has occasionally 

 been confused with pacifica, which it closely resembles {\)\). 24, 25); the latter is a tropical and 

 sub-tropical species. In my own e.xperience, with the Research and Siboga collections, this 

 species unifomily avoided the warm surface water, preferring the lower epiplankton and upper 

 mesoplankton. 



Spadella cephaloptera Busch. (Chart IV). 



L o c a 1 i t i e s : 



Coast of X.W'. Kurope; Mediterranean. 

 Definitive observations: 



Neritic, often between tide marks. 

 N. limit: 59° N., 3° \V. 

 S. limit: Messina. 

 Temperatures: M.A. 9° 5 to 19°. 



l) VanhöFFEN's record of haiiiala in the Karajak-fjord al o falhuins and 6' C. has been accidentally omilted. 



