6 bulletin: museum of comparative zoology. 



3. Stauroteuthis hippocrepium, sp. n. 



(Plate 1, Fig. 1 ; Plate 2, Fig. 1 ; Plate 3, Figs. 1-4.) 



Habitat. — Station 3374, southwest of Malpelo Island ; March .3, 1891 ; lat. 

 20 35' N., long. 83" 53' W., 1823 fathoms ; green ooze ; temperature, surface BO®, 

 bottom 36.°4 ; one specimen, No. 7942. [H. 47.] 



The Body is ovoid, about half as long again as broad ; the mantle-opening, as 

 usual in the genus, closely surrounds the base of the siphon, which is com- 

 paratively small and subulate. What remains of the fins (Plate 3, Fig. 2) is 

 muscular, flattened, pointed, and directed outwards and forwards ; at the base 

 of each is a gently hollowed, subtriangular surface, which during life articulated 

 with the external surface of the anterior end of the dorsal cartilage (Plate 3, 

 Fig. 3). There are, however, traces of a membranous expansion on the ante- 

 rior edge of the fin. The dorsal cartilage is horseshoe-shaped (Plate 3, Fig. 1) 

 and disposed in the horizontal plane of the body, with the concavity directed 

 forwards : its surface is smooth, without any characteristic markings or 

 prominences. 



The Head is so macerated that no description of it is possible. 



The Arms are subequal, and rather stout, soft, and tapering, rounded on the 

 aboral aspect, wedge-shaped on the oral, the row of suckers occupying the 

 narrow end of the wedge. All have lost their tips so the measurements given 

 are merely approximate ; their original length, however, would be from 5 to 

 10 mm. greater than the dimensions here given. The umbrella is entirely 

 wanting, but it appears to have been attached directly to the arm, so that 

 there was no intermediate web. It is impossible to ascertain how far the web 

 extended on the dorsal side of the arm, but on the ventral its attachment ter- 

 minated nearly halfway up the arm about the 25th sucker, as is shown by the 

 presence in that position of a horny induration (Fig. 4) somewhat resembling 

 that in S. meangensis (Iloyle, '86, Plate 11, Fig. 2). The suckers are upwards 

 of 50 in number, and of tlie usual form, the largest being just over 1 nmi. in 

 diameter. The cirri are very small and begin as minute papillae only percep- 

 tible with a lens between the fourth and fifth suckers ; they extend up the 

 arms V)eyond the attachment of the web on the ventral aspect, but how much 

 further it is impossible to sjiy. 



The color, when ciiptured, is shown in Plate 1, Fig. 1, Plate 2, Fig. 1. 



Dimensions. 



mm. 



Length, total about 80 



Knd «if body to niantle-inargin 2-3 



Brc'a<ltli of body I'O 



Breadth of lii-ad 22 



Length of fin > 28 



IJrcailtli of fin (at oriRin) 13 



Diameter of liir^ji'st sucker on arm 1.2 



* The length of tJic fin is measured from tlic root outwards towards the tip. 



