28 MUSEUM, BROOKLYN INSTITUTE OF ARTS AND SCIENCES. 



otocysts develop simultaneously. When set free the medusa has eight well 

 developed tentacles, and eight marginal sense organs ; each containing two 

 spherical otoliths (Figs. 41, 42). 



SCYPHOMEDUSAE. 



Tamoya haplonema, F. Muller. 



Figs. 61-6 Jt, Plate VII. (Fig. 60?.) 



MOlmk, F., 1859 ; Abhandl. Naturf. ges. Halle , Bd.V.. p. 1, Taf. I., 11. 

 Agassiz, L., 1863 ; Cont. Nat. Hist. U. S., Vol. IV., p. 174. 

 Haeckbl, E., 1880 ; Syst. der Medusen, p. 443. 



Young medusa ? "Tamoya punctata," Fewkbs, J. W., 1883; Bull. Mus. Comp. Zool. at Har- 

 vard Coll., Vol. XI., No. 3, p. 84, PI. I., Figs. 4-6. 



The young of the Charybeidae are so different in appearance from their 

 adults, and the characteristic structures, observation of which is necessary 

 for their classification, are so late in developing that it is all but hopeless to 

 attempt to determine them. For example: the young specimens called 

 "Tamoya punctata" Fewkes (Fig. 60, Plate VII) are exceedingly abundant 

 in the Bahamas during the spring and summer, whereas the adult is unknown. 

 When young they swim near to the surface while it seems probable that 

 the adults sink to the bottom. 



However, the young "Tamoya punctata" lacks all trace of gastric cirri, 

 gonads, velar canals, or well developed pedalia; and we are therefore unable 

 to state whether it be the young of Tamoya or Charybdea. Moreover, the 

 exumbrella of the young Charybeidae are usually besprinkled with prominent, 

 more or less pigmented, clusters of nematocysts which are often arranged in 

 definite rows. These either lose their regular order or become much less prom- 

 inent in the adult, so that while they are a most conspicuous feature of the 

 young they are quite inconspicuous in the mature animal. We see, therefore, 

 that the names of immature forms, such as "Tamoya punctata," Fewkes; 

 "Charybdea aurifera," Mayer; and "Charybdea verrucosa," Hargitt, have 

 practically no significance. 



It seems possible, however, that "Tamoya punctata," Fewkes, is the young 

 of Tamoya haplonema, F. Muller. 



Tamoya haplonema is widely distributed, having been found on the coast 

 of Brazil; in the West Indies; at Beaufort, North Carolina; and in Great 

 Peconic Bay, Long Island, New York. Our Figures, 61-64, were obtained 

 from a specimen captured at the last named place early in September, 1902. 



