ON CTENOPHORES OF THE NEIGHBOURHOOD OF MISAKI. 463 



p. 44) have given the number of combs in the rib in question in that 

 species to be four, I find it to be 12-14 ' n tMe larger, and 8 or less in 

 the smaller, specimens of C. amphitrites at my disposal, It appears 

 that in C. veneris also, the number is not constant, since DELACE and 

 HÉROUARD mention it to be 4-6 (1901, p. 751), while FOL has 

 represented 6-7 combs in his figure (1869, PI. ii, fig. 6). Thus, it 

 seems futile to lay much weight on this point. The difference of 

 colouration between the two species probably affords a more reliable 

 criterion for distinguishing them. As remarked by BlGELOW (1912, p. 

 397), the occurrence of the yellowish tint in various parts of the body, 

 coupled with the presence of a vermilion band along the oral margin 

 on either side of body, constitutes a characteristic feature of C. 

 amphitrites. 



Cestum amphitrites has hitherto been recorded exclusively from 

 the Eastern Tropical Pacific. BlGEi.ow described a form from the 

 Maldives under the name of C. pectinalis (19O4, p. 267, PI. viii, fig. 30), 

 but this is probably specifically identical with the form just mentioned. 

 It is doubtful if Eschscholtz's C. najadis (1829, p. 23, PI. i, figs. 1- 

 i c) from the South Seas can likewise be referred to C. amphitrites . 

 since he has mentioned the occurrence of primary tentacles in his form 

 and has given clear figures of these. 



Genus Beroë, Browne. 

 6. Beroë cucumis Fabricius (Pl. VII, fig. 5). 



Beroë cucumis. Eschscholtz, 1829, p. 36. Vanhöffen, 1903, p. 7. Moser, 1903, 



Bestimmungstabelle.- Römer, 1903, p. 81. Moser, 1907, p. 453. Moser, 



1908, p. 24. Mortensen, 1912, p. 83 (partim). Mayer, 1912, p. 52, PI. 



xv, fig. 67, Pl. xvii, fig. 76. 



hlya roseola, L. Agassiz, i860, pp. 270, 296, Pis. i, ii. A. Agassiz, 1865, p. 36. 



The body is fleshy and mitre-shaped, compressed in the direction 

 of the tentacular axis. It varies markedly in the ratio of length and 

 breadth ; the pharyngeal axis may be 3/4 as long as the vertical axis, 



