I 

 400 bulletin: museum of comparative zoology. 



that there is no discontinuity between the West Indian and Medi- 

 terranean forms In the characters which have been used to separate 

 them. These are the number of velar canals per octant, C. marsujnalis 

 having three, occasionally four, C. xayviachana described (Conant, 

 1897, 1898, Mayer, 1910) as having two; and size, C. marsiqnalis 

 being the larger. But the present specimen has three canals in two 

 of the octants, two in each of the other six; and it is of about the same 

 size as C. marsupialis as described by Mayer (40 mm. high by 30 mm. 

 broad). It is apparently true, however, that adult Mediterranean 

 specimens are usually larger, and have more velar canals, than West 

 Indian. x\nd for this reason it is wisest to retain the name xayviachana 

 for the American variety. 



Charybdea alata Reynaud. 



Charybdea alata Reynaud, 1830, p. 95, pi. 33, fig. 1; Vanhoffen, 1908b, p. 34, 

 fig. 3, 4; Mayer, 1910, p. 510. 



The collection contains four young Charybdeas from Stations 

 10,196, 10,200, 10,208, surface hauls, which are best referred to this 

 species, though positive identification is impossible, because of im- 

 maturity. 



The most striking feature of these specimens is their large size, for 

 though only the first traces of gonads are visible, they range in height 

 from 42-49 mm.; in diameter from 29-32 mm., with pedalia 20-21 

 mm. long. 



In every case there are three velar canals per octant. Those next 

 the tentacles are in\'ariably branched dichotomously once or twice; 

 of the others (i. e., the two, in each octant, next the rhopalial frenulum), 

 some are simple, some dichotomously branched near their tips; some 

 with small, irregular side branches. This, of course, suggests that at a 

 later stage in development all the canals would be branched; but 

 there is no evidence of future anastomosis. The gonads, though 

 visible in all three specimens, consist merely of narrow, linear bands, 

 hardly 1 mm. broad, obviously a very young stage. 



The rhopalia are not in good enough condition to allow a description 

 of the eyes. 



These specimens are undoubtedly identical with the somewhat 

 larger examples recorded by Vanhoffen (1908b) as C. alata, with which 

 they agree even to minor details; for further discussion see Van- 

 hdfPen (1908b) and Mayer (1910). 



