ARGONAUTA ARGO AND THE HECTOCOTYLI. 91 



sucker-side towards the mouth, and so inverted in consequence of the 

 Hectocotylus being bent back, that one looks upon what was previ- 

 ously the inner surface of the sac: the chromatophora glimmer 

 through only indistinctly. The margins of the cleft lie in the con- 

 cavity of the first flexure ; one margin passes before, the other behind 

 the thick end of the Hectocotylus ; both unite at * on the dorsal side. 

 Between the edges and the white streak which indicate the seminal 

 sac there is a pit, whose inner surface is formed by what was pre- 

 viously the outer surface of the sac. Where the sucker-bearing part of 

 the Hectocotylus passes into the filiform appendage (penis), the lobe 

 appears on the back, and from this on each side a fold passes on to 

 the appendage. 



[T H. H.] 



