38o DISCOVERY REPORTS 



arm-length. In the remarkably low rhachidian mesocone it approaches B. diaphana 

 (Thiele, 1915, fig. 60). 



A very peculiar feature, which may be accidental, is seen in the surface tissues of the 

 mantle. The epidermis is free from the underlying viscera, and encloses a spacious 

 cavity in which the viscera and surrounding body-wall, by reason of their small size, 

 are suspended free of the epidermis. I am unable to say if the absence of the subcut- 

 aneous gelatinous layer is natural, or caused by some accident of preservation. It seems 

 to me that the latter is most unlikely. 



Remarks. I treat this form as a variety of E. massyae rather than as a distinct species, 

 because on the whole the general facies is quite like that of ?nassyae. The radula and 

 funnel-organ certainly display marked differences. But for the time being I think the 

 bulk of the resemblances is more important. As in the case of A Iloposus hardyi (p. 397) 

 we have to deal with a marked and peculiar character (in this case the absence of the 

 subcuticular gelatinous layer), the precise morphological and systematic importance 

 of which we cannot yet decide, as we do not know if it is not produced by accident. 



Vitreledonella translucida, n.sp. 



St. 273. 31. vii. 27. 9° 38' 00" S, 12° 42' 30" E. 200-230 (-0) m. Young-fish trawl: one (J. 



Dimensions {in mm.). 



Mantle, length (eyes to apex) 41 



Mantle, width, "^'o length 68 % 



Head, width, % mantle-length 51 % 



Weh, maximum depth '4 (') 



Suckers, maximum width 2-4 



,, minimum width i"0 



Description. The large and rather narrowly ovoid mantle is very unlike that of 

 V. richardi (Joubin, 1924, pi. i), alberti {id. loc. cit. pi. ii) and V. ingeborgae {id. 1929 b, 

 p. 18: fig. 40 seems to show a longer visceral sac than the text would suggest). The 

 head, as in Joubin's species, is extraordinarily short. The eyes are small and prominent. 

 Most of the arms have had their extremities damaged, but I am under the impression that 

 they are in the order 1,2,3,4. They are relatively very short, being about 54 per cent of 

 the total length, as compared with 72 per cent in V. ingeborgae (240/330 mm.), 78 per cent 

 in richardi and 71 per cent in alberti (the dimensions of Joubin's species being taken from 

 the figures and therefore subject to a slight correction). The arms are thick and clumsy 

 (though very transparent and delicate) over the greater part of their length, becoming 

 rather rapidly thinner at the extremities. None of the apical suckers are preserved, except 

 on the hectocotylised arm, so that I am very uncertain as to the total number. There are 

 a maximum of twelve left on one arm, and I am inclined to believe that there were 

 about eight smaller suckers beyond these, i.e. some twenty in all. On most of the arms 

 there are seven to eight small and very widely spaced suckers, followed by about four 

 much larger and more closely opposed ones. These (see above) were probably succeeded 



