66 U.S. NATIONAL MUSEUM BULLETIN 234 



The tentacles are short and slender, nearly equal to or much less 

 than the diameter of the sessile arms. They are usually so retracted 

 that only the clubs project from the pockets. The stalks are roimdish 

 in cross section, and bear clubs which are greatly variable in length, 

 ranging from very small and compact ones to elongate clubs which 

 occupy about half of the stalk. The suckers are quadriserial, in about 

 16 transverse rows, and are nearly uniform in size, only gradually 

 reducing in diameter towards the tips. 



The radula was not examined. 



Spermatophores were numerous in the males and are small and 

 slender. Their condition did not permit detailed description. Several 

 females bore spermatophores attached to their skin at various points. 

 In one they were attached as a fringe on the base of the ventral arms; 

 in another they formed a broad patch on the midventral region of 

 the head and on one they were attached to the right side of the mantle 

 near the anterior margin. 



In aU the lots examined, the males were considerably smaller in 

 total length and mantle length than the females, and because of the 

 long neck, the males have a relatively smaller mantle. 



The coloration in alcohol consisted of a general yellowish hue upon 

 which were superimposed numerous reddish-brown pigment spots. 

 On the dorsum of the mantle, head, and arms, these chromatophores 

 are large and often crowded, on the arms yielding a barred effect. 

 On the sides and ventraUy the pigment spots are small to minute and 

 more scattered. The whole area of the adhering organ has a purplish 

 cast. Within the mantle cavity the viscera are covered by a thin 

 membrane containing a few large reddish-purple spots. 



Measurements and indices of 10 males of Idiosepius pygmaeus 

 Steenstrup, 1881, are: 



Type. — Zoological Museum, Copenhagen. 



Type Locality.— 4°20' N., 107°20' E. (South China Sea). 



Discussion. — Four nominal species of Idiosepius have been de- 

 scribed. Steenstrup described pygmaeus from two specimens in the 

 museum at Copenhagen in 1881. The second was described by 

 Ortmann from Japan in 1888, as /. paradoxus, and in 1894 Joubin 



