180 oMMASTHKl'lll - 



O. SLOAMI. (ray. 



Body cylindrical, rather tapering behind : lins rhombic, rather 

 more than one-third the length of tin- hod\ : arms compressed. 



the third pair acutely liimcd, with a narrow rayed membrane on 

 the inner edge oi' the ventral side; tentacles slightly keeled 

 externally, base half naked; cups of lower part small, in two 

 rows, of middle in four rows, the seventh pair of the central 

 series largest (rings with distant teeth all round), of the apical 

 part in three or four rows. 



New Zealand ; Indian 0. 



Described from specimens in Mus. Brit., and not figured. The 

 description does not indicate any great difference from the two 

 preceding species. 



t f t Second and third pairs of arms with a broad, membranaceous fin <>r 



wing on the inner edge of the ventral side, supported by radiating fleshy 



rays arising from the base of the cups. Cups in two distinct 



rows ; ventral part of the mantle free from tJie head. 



O. BARTKAMM. Lesnenr. PI. so. ligs. :ji;i. :\\\-2. 



Body elongate, cylindrical, acuminate posteriorly ; tins dilated. 

 rhomboidal, the angles acute; head short: arms short. biangu- 

 lated or t riangulated dorsally : tentacles large, short. li:mgulated. 

 Shell very narrow, the extremity enlarged. 



Total length. 10 inches, length of body. (\ inches. 



The chromatophores are aggregated into ;i dark dorsal band. 

 West Indies ; Gulf Stream ; Gape of Good Hope? 



t f t t Second and third pairs of arms with a broad membranaceous fin on 



the inner edge of the ventral side, supported by radiating fleshy rays ; 



cups compressed so as to be generally in a single series. 



O. OUALAMI -:\si>. Lesson. PI. s|. fig. :>r,s. 



Body elongated, cylindrical: (ins terminal, broad, transverse: 

 arm- short, unequal, furnished with one row of cups, tentacles 

 much longer than the anus. Shell elongate, narrow. 



Total length about (i inches. 



Indian Ocean ; Cape of Good Hope ; Pacific Ocean. 



o. TBYONII, <iabb. Pi. &1, Bgs. 372, 373. 



Body elongated, cylindrical, tapering to a point behind: tins 

 transversely rhomboidal. between our-tliinl and one-fourth the 

 length of the body : arms >hrt. compres>fd. robust, compara- 



