110 CHAPMAN JONES ON THE SECONDARIES IN PINNULARIAE. 



the Pinnulariae near it, and I do not find anything else on the 

 slide of which it might be a part. 



A seventh photograph was exhibited, showing a girdle, x 

 1,250. Illuminated with a solid central cone, N.A. I'O. The 

 dotted membrane at the margin of the girdle is curved round 

 to approximately a right angle to the face of the girdle, so that 

 this might project into the frustule and thus lie under the 

 costae. Girdles like this are not rare. 



Journ. Quckctt Microscopical Club, Ser. 2, Vol. XIII., No. 79, November 1916. 



