^Challenger'' Cephalojioda. 191 



curving evenly to a pointed posterior extremity. Tiie fia is 

 nearly one third the breadth of the body, extending from the 

 anterior margin of the mantle to within 4 millim. of its fellow 

 at the posterior extremity. The mantle-margin projects to a 

 considerable extent over the head dorsally, and is slightly 

 emarginate ventrally. The siphon is long, reaching up to 

 the interspace between the ventral arms. 



The Head is of medium breadth and the eyes prominent. 

 The Arms are subequal, their order of length being 4, 3, 

 2, 1 ; they are a little more than half as long as the body ; 

 the dorsal are the smallest and subconical, the ventral wide 

 and with a narrow web on the outer aspect ; they all taper 

 gradually to fine points. The suckers are in four series 

 throughout, pedunculate, oblique, and notched proximally 

 and distally, and with meridional grooves on the margin ,• the 

 horny ring has about twenty blunt triangular teeth on the 

 distal semicircumference, and is surrounded by a broad papil- 

 late area. The hectocotylus is not present. The umbrella is 

 but slightly developed, reaching in its greatest extent (between 

 the third and fourth arms) only to the fourth row of suckers. 

 The huccal membrane has the usual seven points, but there is 

 no spermatic cushion. The outer lip is moderately thick and 

 longitudinally ribbed j the inner is provided with many rows 

 of elevated rounded papillse. 



The Tentacles are about as long as the mantle, and have 

 stout three-sided stems ; the club occupies about one fourth of 

 the whole length, and extends fully half round the stem ; a 

 protective membrane is found at either side of them and a web 

 along the dorso-median aspect of the club. The suckers are 

 very numerous, minute and closely packed ; the horny ring has 

 about eight or ten stout distant teeth on the distal margin. 



The Surface is for the most part smooth, but there are 

 about five elongated elevations down each side of the body 

 near the origin of the fin, and a few minute papillge on the 

 dorsal surface. 



The Colour is a dull purplish grey above, pale ochre 

 below. 



The Shell is roughly elliptical in outline ; the anterior 

 extremity is bounded by two straight lines forming a blunt 

 rounded angle ; the sides curve evenly outwards (the greatest 

 breadth being a little anterior to the middle) and form a 

 bluntish point behind. The chitinous margin is narrow and 

 vanishes in the median ventral line behind. The dorsal sur- 

 face is rough, with granules arranged in rows parallel to the 

 anterior margin ; three slightly elevated tracts diverge from 

 the spine to tlie three anterior angles. The ventral surface 



14* 



