i86 fe * *-■« lum I '} m ?: z mm:'mr~m-r z -mm 



220 mm. are 210 mm. in the total length, 22 mm. in the breadth and 170 mm. in 

 the length of the vane. 



The specific characters resemble those of Gonatiis fabricil (Lichtenstein), ex- 

 cept in the tentacular suckers and radula, by which both species are easily distin- 

 guishable, as described elsewhere. 



The body is large, soft and nearly choroidal, being easily mutilated. The 

 mantle, cylindrical at the anterior half, tapers towards the posterior end, and ter- 

 minates in a slender posterior portion of about 1/3 of the whole length, and it has, 

 at the ventral anterior margin, a broad emargination bounded laterally by two angu- 

 lar projections, and at the dorsal anterior margin, a slight angular median pro- 

 jection. The fins are broad, the total breadth being about equal to 3/4 of the mantle- 

 length, and together nearly rhomboidal in shape with a notching at the anterior at- 

 tachment, and extending a little backwards beyond the posterior end of the mantle ; 

 their length are a little longer than half that of the mantle. 



The head is about as broad as the mantle-opening and shows, at the ventral 

 surface, a distinct siphonal excavation which is marked by a faint fold of skin along 

 the boundary edge, and in a well preserved specimen, the anterior middle portion 

 shows several longitudinal folds of skin. The olfactory crest of the neck consists 

 of two semicircular folds, the ventral fold having a small membrane on the top. 

 The eye-openings have a deep anterior sinus, the dorsal margin of which is markedly 

 thickened. The collar-portion of the siphon is broad and free along the whole 

 posterior margin around the neck. The siphonal resisting cartilage is distinctly 

 broader than that of Gonatiis fabricii, being nearly pear-shaped in contour tapering 

 forwards, and having a broad median groove which also narrow towards the anterior. 

 The pallial cartilage corresponding to the above is a longitudinal ridge which is not 

 simply linear as occurs in Gonatiis fabiicii, but becomes much broader backwards, 

 and rises highest at the anterior. The resisting cartilage of the nape is of cocoon- 

 shape being a little expanded at both ends, with a longitudinal median groove 

 marked laterally by 2 ridges, and it has a shallow sinus at each side of the groove 

 at the anterior terminal margin. 



The arms are subequal, the formula of arm-length being 2>3>i%:4, and the 

 longest arm is about half as long as the mantle. The webs of the outer surfaces, of 

 average breadth, are developed in the usual manner. The umbrella, very narrow, 

 as in Gonatiis fabricii. The ventral arms have only suckers about 130 in number, 

 arranged in 4 series, those of the 2 inner rows being a little larger. The lateral and 

 dorsal arms have 2 marginal series of small suckers and 2 inner series of slightly 



