286 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The rostral fin (pre-oraJ lobe) of 71. calif omit use is 

 small, while that of B. indicum is well developed and 

 prolonged to a length of 2 mm. in a specimen of 25 mm. 

 total length. This difference together with the difference 

 in the arrangement of the myotomes certainly justifies the 

 creation of a new species hut most decidedly not of a new 

 sub-genus. 



Kirkaldy expressed doubt as to the exact position of 

 B. pelagicum. I think there is no doubt as to its being 

 a species of Branchiostoma. Gunther distinctly states 

 that it has a double row of gonads, and it is highly 

 probable that its metapleural folds are symmetrical; in 

 which case it is certainly a species of Branchiostoma. 

 The absence of oral cirri is, no doubt, a result of its 

 pelagic life. The sedentary animal would require the 

 cirri to cause currents of water to pass through the mouth, 

 but the pelagic animal, in virtue of its motion through tne 

 water, would set up such a current without the aid of 

 oral cirri. Their absence in this species, therefore, is 

 not remarkable. The enlarged eye spot is another result 

 of pelagic existence. 



We shall now consider B. nakagawoiy the new Japanese 

 lancelet. Andrews 1 records this species as Branchiostoma 

 sp., suggesting that it showed great affinity with B. 

 belcheri, and placing it provisionally in that species. 



Little was then known about B. belcheri as few specimens 

 had been examined. The descriptions were very vague and 

 Andrews hesitates to decide the point, but says that lk the 

 geographical distribution of this species favours this 

 conclusion (that the species is B. belcheri) since we may 

 easily suppose il extended from Borneo (where B. belcheri 

 was fnsl Pound) to - Japan, as il is already known south to 

 the Prince of Wales Island and is thus of wide distribu- 

 ; Zool. Anzeiger. I 



