SEA-FISHERIES LABORATORY. 



381 



Pig. 3. — Photo-micrograph of a plankton haul showing (a) Biddulphia 

 mdbiliensis, forma regia ; and (b) B. mob., f. sinensis. 



In the XVIIIth Annual Eeport (for 1909, p. 



we recorded the discovery of Biddulphia sinensis in Port 



Erin Bay for the first time on November 9th, 1909. We 



also showed that it increased in numbers from 400 



specimens on November 9th in the coarse net to 1,600 



specimens in a haul with the same net on November 13th, 



and for the rest of the year the numbers varied from 



1,000 to 800 for the coarse net. We then stated : 



The view is definitely held by Ostenfeld that this is a 



case of an exotic species which was introduced 



accidentally (e.g. by a ship from the East) into 



European waters near the mouth of the Elbe, probably 



in September, 1903 ; and the rate of dispersal from that 



point is used as an indication of the presence and rate 



of flow of currents. If Ostenfeld is right in bis 



