SEPIA. 141 



3. S. biseria'lis*, (bisserialis) De Montfort. 



S. bisserialis, (De Montfort) Yerany, Moll. Med. i. p. 75, pi. 26 ; F. & H 

 iv. p. 241, (shell) pi. PPP. f. 2. 



Body oblong, of a delicate greyish-pink colour, closely 

 covered with minute purplish-brown chromatophores or pig- 

 ment-spots of various shapes and sizes ; those on the underside 

 or belly are larger and more scattered, the spots on the upper- 

 side or back being smaller and very crowded : mantle tough, 

 with a membranous outer skin : fins equal in width, extending 

 from a little below the upper edge of the mantle to near the 

 base : tentacles exceeding in length the mantle and head to- 

 gether ; stalks slender and smooth ; club very small, marked 

 obliquely on the outer side with rows of purplish-brown specks, 

 and irregularly studded underneath with small suckers, besides 

 2 or 3 much larger ones at the base of the club ; the pedicles 

 of the suckers are long : funnel conical and wide : head large, 

 broadly triangular : eyes prominent, resembling those of a fish : 

 arms short and thick, the ventral or lowest pair by far the 

 largest; arm-suckers irregularly arranged, some of the arms 

 (especially in certain specimens) having 2 either symmetrical 

 or alternate rows, while other arms in the same specimens 

 have 3 of such rows ; these suckers are nearly equal in size 

 from the base until they approach the tips, where they become 

 minute and crowded; all the arms, except the ventral pair, 

 are slightly webbed at the base. L. (exc. tent.) 3. B. 1*5. 



Shjell narrowly lanceolate and very slender ; back or upper- 

 side firm, of a delicate rosy fleshcolour, its margin being 

 covered with a broad and thin yellowish epidermis ; this side 

 is slightly shagreened, and exhibits all the layers of growth, 

 of which more than 100 may be counted ; the medial ridge is 

 distinct and narrow throughout ; underside soft, white, raised 

 at about \ of the distance from the front, to which it slopes ; 

 the excavated part occupies the remaining |; this part is 

 of a silvery hue, and is marked down the middle by a distinct 

 furrow, besides several slight longitudinal lines ; the excavated 

 part is furnished at the sides with a slender rib, which forms 

 a curve at the base ; the whole surface of the underside is 

 microscopically fretted : cartilaginous fringe narrow and thin 

 on the upper part, much broader and raised like the sides of a 



* In two rows ; from the arrangement of the arm-suckers. 



