hoyle: reeorts on the cephalopoda. 23 



The young ypecirneu [H. 129] shows a noticeable resemblance in general 

 appearance to the Octopus venustus of Rang ('37, p. 66, Plate 93). This 

 authority, however, figures the suckers in two rows, though he adds that 

 they are "assez peu apparentes." The resemblance is in any case sufficiently 

 strong to raise the interesting question whether the small pelagic forms de- 

 scribed as Octopus hrevipes F6russac and d'Orbigny ('35, p. 22), 0. capensis and 

 0. dubius Eydoux aud Souleyet ('52_) may not be allied to Eledonella. 



JAPETELLA. 

 Japetella Hoyle, '85a, p. 231 ; '8S, p. 109. 



24. Japetella prismatica. 



(Plates, Figs. 10, 12.) 

 Japetella prismatica Hoyle, '85 a, p. 231 ; '86, p. 109, Plate 9, Figs. 1, 2. 



Habitat. —SiixtUm 3414, off Tehuantepec ; April 8, 1891 ; lat. 10° 14' 

 N. long. 96° 28' W., 2232 fathoms ; green mud ; temperature, surface 82°, 

 bottom 35. °8 ; one specimen $ , No. 7945 B. [H. 36.] 



I have compared this specimen with the type in the British Museum 

 (Natural History) and have satisfied myself that both belong to the same 

 species : there are, however, one or two points which call for special notice. 



In the " Challenger " Report it is stated (p. 108) that there is a valve in 

 the siphon, but I have ascertained by comparison of this example with the 

 type that I was misled (as in the case of Eledonella diaphnna) by the tip of the 

 funnel-organ having become detached, producing a deceptive appearance of 

 a valve. The form of the funnel-organ in the " Challenger " specimen is 

 shown in Plate 5, p'ig. 12. 



The other point relates to the median septum in the branchial cavity. In the 

 " Challenger " specimen such a septum appeared to be absent, but in the present 

 example there is a narrow delicate ridge running along the median ventral 

 line of the interior of the mantle, which mav be the remains of such a septum, 

 though I can find no trace of its attachment to the visceral sac. Led by this 

 discovery, I have re-examined the "Challenger" type and find there also 

 traces of a similar ridge on the inner surface of the mantle. It seems, there- 

 fore, quite within the bounds of possibility that specimens in a better state of 

 preservation might show a complete septum, in which case there would be no 

 further cause for separating the genera Eledonella and Japetella. Although I 

 think it very probable that in tlie future these two genera will be united, I 

 think it advisable pending further evidence to retain them as distinct. The 

 suckers on the third pair of arms of the " Albatross " s]iocimen are much 

 enlarged (Plate 5, Fig. 10), exactly as figured by Verrill ('84, Plate 32, Fig. 

 2) in the case of Eledonella pugmaea. This is almost certainly a form of hecto- 

 cotylization and is an additional point of similarity between these two geuera. 



