168 THE MEDUSAE. 



two to five otoliths. After preservation in formalin for two years most of 

 the otoliths are destroyed. 



Gonads. — All the specimens have gonads, though in the smaller ones 

 they are but slightly developed. Their position appears to be an important 

 specific character, for like the length of their extent along the radial canals 

 it is remarkably constant. They commence close to the bell margin and 

 occupy the distal one third to one fourth of the radial canal on the subum- 

 brella surface. None of the specimens showed any trace of the formation 

 of gonads on the peduncle. Even at early stages they occupy this same 

 portion of the canals, and they increase in size chiefly by thickening, their 

 increase in length only keeping pace with the general growth of the indi- 

 vidual. The series contains both males and females. 



Color. — In life the gonads were pale green; in the preserved specimens, 

 however, both they and the manubrium have faded to a pale opaque yellow. 



The absence of marginal knobs and of lateral cirri at the bases of 

 the tentacles, and the shortness of the gonads, clearly separate this species 

 from the West Indian form, E. coerulea. The number of tentacles, though a 

 variable feature, may likewise prove to be of specific significance, since 

 L. Agassiz ('62) states that in large specimens of E. coerulea measuring 1-^ in. 

 in diameter by 1 in. high there may be as many as thirty-five per quad- 

 rant. In specimens of E. coerulea 10 mm. in diameter he counted only 

 thirty-two tentacles, but there were in addition ninety-six bulbs, which 

 may later develop into tentacles, thus producing the large number seen 

 in adults. The exact relation of E. scintillans to E. indicans cannot be deter- 

 mined until the marginal organs of the latter are more fully described, but 

 the form of the gonads and that of the peduncle appear to separate the two. 



Octocanninae Maas, 1905. 



Octocannidae Haeckel ('79). 

 Eucopidae with eight radial canals. 



OctOCanna Haeckel, 1879. 

 sens. em. Maas (: 05) ; Browne (: 05''). 



Octocanninae with eight simple radial canals; with well-developed manu- 

 brium with octagonal basal region ; mouth with eight lips. 



The descriptions of adult specimens of this genus by Maas (: 05) and 



