REPORT ON THE CEPHALOPODA. 131 



however, be owing to the smaller size and presumably less complete development of the 

 latter, which had unfortunately lost the horny rings of its suckers, so that comparison 

 of these parts was impossible. 



The two specimens of the present species furnish an admirable illustration of the sexual 

 differences in the genus Sepia; the structure of the hectocotylised arm has been 

 described above, but in addition to that it is seen that the proportions of the body are 

 very different ; the breadth being 52 per cent, of the length in the male and 57 per 

 cent, in the female. This difference is still more pronounced in the shells, the breadth of 

 the male shell being only 32 per cent, of the length, while in the female it is 37 per cent. 



Appellof has had the good fortune to examine specimens of this species in which the 

 tentacles were present, and I have inserted above a translation of his description of those 

 organs. He adds also some interesting and valuable remarks on the gradual development 

 of teeth in the suckers and on the relations of the species. 



Sepia elliptica,^ Hoyle (PI. XIX. figs. 14—24). 



1885. Sepia elliptica, Hoyle, Diagnoses II., p. 189. 

 1885. „ „ Hoyle, Prelim. Rep. II., p. 293. 



Habitat. — Station 188, Arafura Sea, south of Papua, September 10, 1874 ; lat. 

 9° 59' S., long. 139° 42' E. ; 28 fathoms ; green mud. Four specimens, one $ , three $ . 



Station 190, Arafura Sea, south of Papua, September 12, 1874 ; lat. 8° 56' S., 

 long. 136° 5' E.; 49 fathoms ; green mud. Four specimens, one $ , three ? . 



The Body is ovoid, broadest one-third from the anterior margin, pointed behind. 

 The Jins are one-third the width of the body, broadest in the middle, extending the 

 whole length of the body, and "approaching within 2 mm. of each other posteriorly. 

 The mantle-margin is not very prominent over the head dorsally. The mantle-connective 

 is rather short and deep, but otherwise normal. The siphon is conical, reaching to 

 within 1 mm. of, or quite up to the space betwe'en the ventral arms. 



TJie Head is very short and broad, the eyes prominent. 



The Arms are subequal, the order of length being 4, 3, 2, 1, or 4, 2, 3, 1 ; they are 

 nearly half the length of the body, and taper evenly to fine points ; there is a distinct 

 but narrow ridge along the fourth arm, and a delicate web along each side of the oral aspect 

 of the arms. The suckers are in four series throughout, and of moderate size, marked 

 with inconstant meridional grooves (fig. 17), and there is a large notch proximally and 

 distaUy in the rim (fig. 19). The horny ring has for the most part no distinct teeth, 

 but is marked in the distal half with shallow irregular notches, which are occasionally 

 more regular (figs. 17, 19). A papillary area surrounds the horny ring (fig. 18). The 

 hectocotylus is developed in about the middle third of the left ventral arm (fig. 16); beyond 



1 So named from the form of the shell. 



