NOTE ON A BRITISH CEPHALOPOD. 



191 



cluh with the central suckers about four times as great in diameter 

 as the laterals, and provided with very acute teeth, separated by 

 interspaces somewhat larger than the breadth of the tooth at its 

 base ; terminal suckers in four rows. 



Habitat. — Britain: Dublin Bay (Ball), Antrim (Museum of 

 Science and Art, Dublin, fde ScharfE) ; North Sea (Captain Gray) ; 

 Plymouth (Marine Biological Laboratory) ; Mediterranean : Naples 

 (Zoological Station). 



Among* the material examined were four males, which exhibited 

 the interesting form of hectocotylisation I now propose to describe 



Fig. 2, — Fin of Illex ehlanm. 



(see fig. 1). The alteration affects both arms symmetrically in 

 their basal portions, but the right arm only is modified to the tip. 

 About 2 cm. from the base of each arm, instead of a sucker, is a 

 flattened bract-like appendage, growing out from a broad base. Its 

 distal margin is slightly notched, and at the inner extremity bears a 

 sharp tooth ; at the outer margin it curves into the general surface 

 of the arm. On the outer side of the oval surface of the arm this 

 appendage is succeeded by three similar ones, gradually decreasing 

 in size. On the inner margin of the arm, alternating with them, 

 are three conical teeth, also directed towards the tip of the arm. 

 The points of all these teeth are tough, and feel almost cartilaginous. 

 Beyond this the left arm presents the normal arrangement of suckers, 

 but the right arm has only two suckers placed near the inner 

 margin ; on the outer margin is a series of conical tubercles, ex- 



NEW SERIES. — VOL. II, NO. II. 15 



