CEPHALOPODA. — BERRY. 



217 



Buccal Membrane eight-pointed, thin, delicate, strongly 

 rugose within, and very deep in colour owing to the large 

 number of minute dot-like chromatophores covering its outer 

 surface. 



frladius (Fig. 3) horn-coloured, its ^, 



midrib showing through the mantle 

 integument as ? conspicuous, dark, medio- 

 dorsal line, not extending into the soft 

 hinder extension of the body ; the free 

 rhachis slightly less than one-fourth the 

 total length ; midrib flanked by a narrow 

 tliickening along it on each side and a 

 weaker submarginal thickening on the 

 wings ; wings thin, broad, their margins 

 obtusely angled at the widest point, some- 

 what less than two-fifths of the length 

 from the anterior end. 



Radula (Fig. 4) simply constnicted, 

 the marginal teeth having simple, 

 arcuate, tapering blades ; remaining teeth 

 conical : of the latter, the median teeth 

 broadest and longest, the first laterals 

 narrowest and shortest. 



Photophores divisible into two principal 

 classes : — (A) those of the general integu- 

 ment, which are exceedingly numerous ; 

 and (B) a series of nine organs along the 

 ventral periphery of each eyel)all. Organs 

 of the general integument (Fig. 2) 

 distributed as follows : — (1) Head and 

 Arms : — Ventral aspect of head with three 

 bands of a depth of about three organs 

 each, the median band splitting anteriorly 

 into two forks running out the inner 

 ventral margins of the ventral arms to 

 their tips, and posteriorly into two forks 

 along the boundary of the funnel groove ; 

 lateral bands continuing along the outer 

 margin of the main body of the arms to their tips, each flanked 

 outwardly by a narrower, less dense, more irregulp.r band, this 

 and its mate continuing along the outer ventral margins of 

 the broad membranous keel of the ventral arms ; ventral 

 margin of eyelid on each side bordered by a single, closely- 

 ranked series of photophores which skips across the lid-sinus 

 and thence runs out along the outer angles of the third arms 



Fis. 3. — Knoplo- 

 teMhi-i gnl'uin-s $ 

 [462] ^ladiup in dors- 

 al aspect ; represent- 

 ed with the wings 

 spread flat. 



