NANOMIA CARA. 



207 



become more numerous and larger, the knob assuming more a ladle- 

 shape (e, Fig. 344) ; there is then ibrmed a still larger row of lasso-cells, 

 extendiiig along the edge, and concealing the others (/, Fig. 344), 

 making a kind of binding when seen from above (g, Fig. 344), where 

 we fmd all the peculiar characteristics of the sole-shaped, lasso-paved 

 knob of Fig. 339, the only difference in the older knobs being the 

 greater size of the outer row of lasso-cells, and their closer packing, 

 which conceals entirely the cavity running into the knob, while it is 

 plainly visible in younger tentacles. 



The perfectly free and open communication we find between all the 

 parts of the community, except the float, is one of their most striking 

 characteristics ; there is not an appendage into which the food taken in 

 by any one of these feeding polyps (Medusae) cannot circulate into its 

 very extremity ; even the scales, which seem in their full-grown state 



Fig. ri44. 



Fis. 343. 







Fip. '.'Ah. 



to consist of nothing but a gelatinous shield, with a very narrow tube 

 passing through the middle, are, when developing, open pouches leading 

 at once into the main cavity of the axis, and even after the buds can 

 distinctly be recognized as undeveloped scales (Fig. 345), the cavity 

 occupies a much greater part of the scale than in the adult, as is readily 

 seen in the different views of one of the scales {a, 6, c, Fig. 345). In 

 the view from above, a, the triangular shape is already apparent ; a 

 profile view, b, shows its greater thickness than in a fully-developed 

 scale, while in an end view, c, it is still quite pentagonal. 



Besides these different kinds of appendages, we find the sexual 

 individuals scattered in small clusters of abortive Medusae near the 

 lower extremity of the axis, generally in the third nearest the terminal 



Fig. 343. a, b, c, cl, tentacular knobs like those of Fig. 339, in different stages of development. 

 Fig. 344. e,f, (J, the same tentacular knobs, still further developed. 



In Figs. 343 and 344 all the figures are seen in profile, except h of Fig. 343, and y of Fig. 344, 

 which are seen from the flat side, to show the arrangement of the lasso-cells. 

 Fig. 345. Young scale ; seen from above, a ; in profile, b ; and endways, c. 



