VELEIJ.A LATA. 



345 



that the smallest Ratariae were taken in the earliest hauls, while the individuals 

 of later cajjtures grow on the whole larger and larger. A month later large 

 specimens might have been abundant. 



The actual dimensions of the shells in a series of Atlantic and Pacific speci- 

 mens is given in the following table. 



Of the one hundred and thirty-eight Pacific specimens which are large 

 enough to show obliquitj' of the crest, seventy-three are "S. W." 04 "X. W." 

 (according to the nomenclature of Chun, '97b). This, together with the fact 

 that the crest is N. W. in all of the five "Siboga" specimens recorded by Lens 

 and Van Riemsdijk (:0S, p. 123), contrasted with Chun's observations of 71 

 S. W. to () N. W. in r. velella, and A. Agassiz's failure to fiiul a single N. W. 

 specimen among the many hundreds of that species which he studied, shows 

 that the N. W. condition is much more common in the Pacific ]'. lata than in 

 the .\tlantic 1'. relella. 



Distribution. The records of V. hita show that it is very generally dis- 

 tributed over the warmer regions of the Pacific, extending northward to Japan, 

 and to Puget Sound. How far it may extend southward is not yet known. 



