CLASSIFICATION OF THE CEPHALOCHORDA. 



293 



Genus II. Asymmetron, Andrews, 1893. 



(Heteropleuron, Kirkaldy, 1895). 

 ( do. Willey, 1901). 



A. cultellum (Peters, 1876). 

 A bassanum (Guntker, 1884). 

 A. lucayanum, Andrews, 1893. 



A. lucayamim, var. caudatum. 

 A. cingalense (Kirkaldy, 1895). 

 A. hectori (Beiiham, 1901). 

 A. maldivense (F. Cooper, 1902). 

 As to which, is the older phylogenetically of the two 

 genera, I think there is little donbt that Branchio stoma 

 is the more archaic, as Willey suggests. For his reason 

 for this statement see his paper on A. cultellum in the 

 Quarterly Journal of Microscopical Science, Vol. 35. 

 Geographical Distribution. 

 General Remarks. — The species of the Cephalochorda 

 are widely distributed over the seas of the Globe, as the 

 following tables show. 



Table I. — Showing Distribution according to Latitude. 





North Latitude. 





Species. 





South Latitude. 





Vr 



*>■ 



CO 



bC 



M 









o 



o 



o 



o 



o 



Oi Q 



Cn O 





CO O 



to o 



M o 





■So 



+= o 



~** 9-> 



+3 O 



■+=> o 



43 9- 



^eT 



o u 



trt- 



o ° 



9 ° 



o ° 



°°? 





^ 



o O 



°o£ 



°o^ 



°o^ 



^& 



o 



o 



O 



o 



O 









1-1 



CM 



CO 



■<* 



iC 



_1_ 



+ 



+ 







I 



+ IB. lanceolatum 

 + \B. belcheri 



















+ 



+ 



+ 



\B. caribba"iim 





+ 



+ 



+ 











+ 



+ 

 + 



+ 

 + 



+ 



B. nakagcnvce 

 B. pelagicum 

 B. elongatum 

 B. californien.se 

 B. capense 

 B. indicum 

 A. bassanum 







+ 

 + 



+ 

 + 













A. hectori 











+ 













+ 



+ 

 + 



A. maldivense 

 A. cultellum 





+ 



















+ 



+ 

 + 



A. lucayanum 

 A. cingalense 

 A. caudatum 



+ 









1 





