994 



PROF. U'ARCT W. THOMPSON ON 



[Dec. 18, 



arms, the ventral ones in the ventral and ventro-lateral arms, 

 converge to unite with the buccal membrane, drawing it outwards 

 at their points of attachment into pouched hollows, above whicli 

 its free margin is produced into pointed lobes. A similar arrange- 

 ment is seen in Jatta's figure of Thysanoteuthis rhombus Tr., in the 

 Xaples Monograph, pi. ix. fig. G. In Ommastrephes the buccal 

 membrane is six-lobed, the anterior and posterior lobes each 

 corresponding to the attachment of two adjacent bridles from 



A. Upper mandible of Ancistmteti/liis. Natural size. 



B. Lower mandible of Ancistroteuthis. Natural size. 



the arms ; and each of these lobes is furnished with two small 

 two-rowed clumps of small suckers. Here the suckers are absent, 

 and the attachments of the two ventral fringes are widely separate, 

 so that the buccal membrane is seven-lobed. The fringes above- 

 mentioned, that lie adjacent to the suckers, are narrow in the 

 case of the ventral arms, but considerably broader in the other 



