H. B. Kirk. — On the Anatomy of Sepioteuthis bilineata. 155 



but a short distance backwards on the outer aspect, being here shortened 

 by a concave border. At the sides they expand and become irregularly 

 oblong in shape. They have a somewhat irregularly waved outline and 

 extend forward beyond the uncus, so as to cover the inner portion of the 

 alae of the upper-jaw. The apophysis extends outwards and backwards 

 with a slight curve, its shortest length being at the median line, where the 

 margin is concave. Its greatest length is within, where the margin is con- 

 vex. The apophysis slopes rapidly from the median line, leaving a well 

 marked keel. 



(Note. — In describing the jaws I have not adhered to the rule of speak- 

 ing of the animal as though it were in a walking position, but have noticed 

 them as they are detached and shown in the drawing.) 



Taste-organ (fig. 3 a). — Within the jaws and on the posterior side of the 

 mouth is the gustatory organ, showing a fairly well-marked division into 

 two lobes. It is soft and uncurved, and under the microscope shows inter- 

 lacing fibres. 



Odontophore (fig. 3 6). — Next follows the broad radular band which 

 works in and out of a socket in the centre of a raised papilla. It is armed 

 with seven rows of silicious teeth. Its upper part is expanded, and has the 

 margins recurved. The lower part has the margins incurved so as to form 

 a cylinder, and it is probable that this part is but little used in mastication. 

 The teeth on the upper part are stronger and stouter. 



The central row of teeth consists of slightly curved, rather stout and 

 obtuse spines, whose bases develope short obtuse prominences, one on each 

 side, giving the denticles of this row a 3-fid appearance. The first lateral 

 row consists of slightly curved spines, somewhat more acute than those of 

 the median row. The spines have the base also developed as in the 

 median row, but the inner basal spine is somewhat shorter than the 

 outer. The next two rows consist of longer curved spines without basal 

 spinules. 



Faucial follicles (fig. 3 d). Next come the two "faucial follicles." They 

 are attached along one side, starting at the tongue and continuing to the 

 commencement of the oesophagus. They are very well developed. The 

 free margin is straight, and when folded over they form a covered channel 

 over the radular socket. 



Salivary glands. — The mandibles, tongue, odontophore, and faucial 

 follicles are contained in the buccal mass, which narrows into the oeso- 

 phagus. Outside the buccal mass, at the commencement of the oesophagus, 

 are two slightly-raised papillae, the lingual salivary glands. Further along 

 the oesophagus, and imbedded in the liver, are two salivary glands with 

 well-marked ducts. 



