ELEDONELLIDAE 



381 



by about eight much smaller ones. The arrangement of the first part of the arm is not 

 unlike that found in V. ingeborgoe, but the extremity of the arm differs. As in V. richordii 

 and alberti the suckers are planted in a gelatinous boss, which raises them well above the 



Fig. 7. V iUeledoiiella traiislncida. Funnel-organ. >: 6-2. 



level of the arm. The enlarged suckers, however, are placed at the ordinary level. They 

 are simple, thin walled, and show scarcely any structural differentiation. The web has been 

 partly destroyed and I am unable to make out its exact form. I believe it attains a depth of 



Fig. 8. Vitreledonella translucida. Radula. 



about J of the arm-length. The mantle-aperture is wide, the funnel short and stout. It 

 contains a well-developed funnel-organ of the same general shape as that of V. richardi, 

 but differing in sundry features (Fig. 7, and Joubin, 1924, pi. vi, fig. 5). There are 

 seven filaments in the outer demibranch. The inner demi- 

 branch is absent as in V. richordi. 



The radida (Fig. 8). Joubin's figure of V. richardi 

 is not like that of translucida, except in general plan. 

 The median tooth of translucida is markedly asymmetrical, 

 and there is an Octopm-Mke. seriation. The admedian 

 has a large median mesocone, small ectocone and 

 shallow base. The second lateral has an obvious inner 

 "heel." The third laterals are long and slender and 

 the marginal plates oblong. The radula is remarkably 

 Octopiis-WkQ and very unlike that of Eledonella and its 

 allies {v. anon). 



The hectocotylus {}) (Fig. 9). The third arm of the 

 left side has the appearance of being hectocotylised. 

 The arm is shorter than its fellows, and on one side 

 there is a narrow lateral membrane (absent from the 

 other arms) like a seminal channel. There are a large Fig. g. Vitreledonella translucida. 

 number of closely appressed small suckers at the extremity Hectocotylus (?). x c. 20. 

 (unlike the other arms). Shortly before the end they terminate in a faintly grooved 



