KEPORT ON THE CEPHALOPODA. 



107 



or absence of a median septum in the branchial cavity. Verrill does not appear to have 

 opened the siphon of his specimen, for he does not allude to a pad in its dorsal wall ; 

 in the Challenger specimen this pad was free at its anterior extremity, forming a valve, 

 but I am not sure that the separation was not artificial. 



Eledonella diaphana, Hoyle (PL IX. figs. 3-6). 



1885. Japetella diaphana, Hoyle, Diagnoses I., p. 232. 

 1885. „ „ Hoyle, Prelim. Rep. L, p. 108. 



Habitat. — Station 220, north of Papua, March 11, 1875 ; lat, 0° 42' S., long. 



147° E.; 1100 fathoms (?) ; Globigerina ooze. One specimen, ses ?. 



Tlie Body is gelatinous and semitransparent ; it is ovoid in form, and considerably 

 longer than broad. The mantle-opening is very wide, extending up behind the eyes on 

 either side. The siphon extends two-thirds of the distance to the umbrella margin, and 

 is truncated at the extremity; it has a thick pad on its dorsal wall, which seems to form 

 a valve by its free tip. There is a median septum in the branchial cavity (PL IX. fig. 4). 



The Head is nearly as broad as the body, and the eyes are large and prominent ; 

 they consist of a larger, darkly pigmented spheroid, from which protrudes the opaque 

 white, smaller, spheroidal lens. 



The Arms are unequal ; the longest (the third pair) are almost as long as the body, 

 and are nearly twice as long as the fourth, which are the shortest, the order of length 

 being 3, 2, 1, 4 ; they taper rapidly to fine points. The umbrella is very small, 

 extending about one-fourth up the dorsal and ventral arms, a little further up the 

 dorso-lateral and lateral arms, and being least developed in the space between the 

 ventral and ventro-lateral arms (fig. 5). The suckers have assumed, probably owing 

 to shrinking, a quadrangular or triangular form (fig. 6) ; they are prominent, and 

 marked by two constrictions, one at the base, separating them from the arm, the other 

 rather more than halfway up. There is no trace of any hectocotylus. 



The Surface appears to have been smooth originally, but the epithelium has been 

 to a great extent stripped off. 



The Colour is very pale yellowish-grey, marked with numerous longitudinally 

 disposed oblong chromatojphores. 



Dimensions. 



36 mm. 

 16 „ 



Length, total, 



End of body to mantle-margin, 



End of body to eye, 



Eye to edge of umbrella, . 



Length, of third pair of arms, 



18 



18 



In the Preliminary Eeport this specimen was recorded as being from the " surface," 

 firstly, on the ground that it was so noted in the manuscript Station Book, kept during 



