12 MUSEUM, BROOKLYN INSTITUTE OF AUTS AND SCIKNOES. 



nuclei and cell material showing little or no trace of cell boundaries (c, Pig. 

 IS''). 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. 15'=) . 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, si, 

 of the manubrium of the parent medusa remains unbroken, and that the en- 

 toderm of the parent medusa, ent., never comes into contact with that of the 

 bud, e n t.b. 



Netocertoides brachiatum, Ma tee. 



Fig. 1, Plate I. 



Mateb, a.. G., 1900; Bull. Mus. Comp. Zool. at Harvard Coll., Vol. XXXVII, p. 45, Figs. 43- 

 44 ; PI. 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 proximal roots of the 

 radial canals are bound to the manubrium by simple mesenteries. The 

 manubrium is broad and disk-like and the mouth 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 common at the Bahamas, but rare at the Tor- 

 tugas, Florida. Seen only in summer. 



Tetracannota coUapsa, Mayer. 



Fig. 32, Plate IV. 



Mateb, A. G., 1900; Bull. Mus. Comp. ZoOl. at Harvard Coll., Vol. XXXVII, p. 46, Figs. 14- 

 16, Plates 7, 8. 



Fbwkbs, J. W., 1883 ; Bull. Mus. Comp. Zo51. at Harvard Coll., Vol. XI, No. 3, Figs. 7, 7a. 



Mature medusa: Bell higher than a hemisphere and 7 mm. in diameter. 



