12 MUSEUM, BROOKLYN INSTITUTl^: OF ARTS AND SCIENCES. 
ouclei and cell material showing little or no trace of cell boundaries (c, Fig. 
15^). These are present at all stages of the developing bud, partially filling 
the gastro-vascular cavity, but they appear to degenerate in later stages, and 
it seems possible that they serve to nourish the bud in its growth. This sup 
position appears the more probable from the fact that the gastro-vascular 
cavity of the bud is never in connection with that of the parent medusa (see 
Fig, IS*") . Fig. 15^ shows a young stage of the bud wherein the entoderm has be- 
come a cup-shaped vesicle, and the ectoderm is hollowing out to form the 
bell-cavity. Fig. 15*^ is a late stage showing that the limiting membrane, .s/, 
of the manubrium of the parent medusa remains unbroken, and that the en- 
toderm of the parent medusa, cut., never comes into contact with that of the 
bud, e n t. h. 
Netocertoides brachiatum, Mayer. 
Fifj. 7. Plate I. 
Mayer, A. G., 1900; Bull. Mus. Comp. Zool. at Harvard Coll., Vol. XXXVII, p. 45, Fi-s. 43- 
44 ; PL 18. 
Bell 3.5 mm. high, mitre-shaped, walls quite thin. Sixteen hollow taper- 
ing tentacles; one at the base of each of the sixteen radial canals. 16-25 small 
tentacles, one or two between each pair of the long ones. Longest tentacles 
are about one-quarter as long as the bell-height and their distal ends are 
tightly coiled. The short tentacles are hardly more than cirri. No marginal 
sense organs. Velum well developed. Eight main radial canals arise from 
the manubrium, but each bifurcates, giving sixteen radial canals, which ex- 
tend straight toward the circular vessel. The eight proxinuil roots of the 
radial canals are bound to the manubrium by simple mesenteries. The 
manubrium is broad and disk-like and the nujuth is at the extremity of a 
short neck, and is surrounded by four simple lips. Gonads within the eight 
main radial canals. The entoderm of the tentacles, radial canals and manu- 
brium is rosin-colored. Quite c(mimon at the Bahamas, but rare at the Tor- 
tugas, Florida. Seen only in summer. 
Tetracannota collapsa, Mayik. 
Fiff. 32, Plate IV. 
Mayer. A. G., 1900; Bull. Mus Comp. ZoiJl. at Harvard Coll.. Vol. XXXVII, p. 40. Fiirs. 14- 
16, Plates 7, 8. 
Fewkes, J. W. 188:5; Bull. Mus. Comp. Zo()l. at Harvard Coll., Vol. XI, No. 3, Fi^s. 7. 7a. 
Mature meduHu: \W\\ higher than a liciiiisithcre and 7 mm. in diameter. 
