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PT?OF. IV AWT W. THOMPSON OS 



[Doc. 18, 



arms, the ventral ones in the ventral and ventrolateral arms, 

 converge to unite with the buccal membrane, drawing it outwards 

 at their points of attachment into pouched hollows, above which 

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

 ment ia seen in Jatta's figure of Thysanoteuihis rhombus Tr.. in the 

 Naples Monograph, pi. ix. fig. 0. In Ommastrephea the buccal 

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

 corresponding to the attachment of two adjacent bridles from 



Fig. 1. 



A. Upper mandible of Ancistroteuthu. Natural size. 

 1» Lower mandible of Ancistroteuthis. Natural size. 



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

 two-rowed clumps of smaU 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 



