80 bulletin: museum of comparative zoology. 



red pigment. The swimming-bells (Figures 109, 110, Plate 33) are dovetailed 

 alternately, one above another, so that theii- velar openings are situated on two 

 diametrically opposite sides of the nectosome (see Figure 108). 



The siphosome is densely covered upon all sides with thick prismatic bracts, 

 or covering scales. One of these bracts detached from the animal is shown in 

 Figure 112. The angular edges of the older bracts are usually smooth, but in 

 the younger ones they frequently display a row of regularly arranged nema- 

 tocyst-bearing papillae (see Figure 113). A single, long, slender canal runs 

 through the substance of each bract. 



The feeding-polypites are somewhat stouter in shape than the dactylozoids, 

 but in other respects are quite similar to them in appearance. They are quite 

 contractile, and their mouths may be expanded, at will, so as to assume a 

 funnel shape. 



The tentacles arise from the bases of the dactylozoids and feeding-polj'pites. 

 Each tentacle gives off a number of lateral branches, each one of which termi- 

 nates in a coiled nematocyst-battery, an ampulla, and two paired finger-like 

 processes (see Figure 111, Plate 33). 



Both male and female gonostyles spring from the siphosome of the same 

 individual. They arise from the ventral side of the siphosome between the 

 dactylozoids and feeding-polypites (see Figure 108). The gonophores arise 

 from the sides of the gonostyles. The male gonophores are long and slender, 

 while the female are short and stout. Both resemble medusa buds and are 

 provided with 4 radial tubes, a circular vessel, and a velum. The genital 

 products occupy the manubrium. The gonophores are borne upon long slender 

 filaments attached to the sides of the gonostyle. These filaments are highly 

 contractile. 



The color of the entoderm of the stem, swimming-bells, feeding-polypites, 

 and dactylozoids is rose-pink. The nematocyst batteries upon the terminal 

 portions of the tentacles are port-wine-red. The gonads and bracts are 

 colorless. 



This si)ecies was found by us at the Tortugas Islands in June, 1897. We 

 also met with it in Suva Harbor. Fiji Islands, in December, 1898. 



Agalma virida, nov. sp. 



Figs. 119-131, Plate 35. 



A single immature individual of this beautiful species was obtained on June 

 6, 1899, at the Tortugas. 



SjKci/ic Characters.— The animal is 3 mm. in length. The float is spherical 

 and almost egg-shaped, and is covered by one of the larval bracts. The pore is 

 a simple round opening at the aboral pole of the float, and is surrounded by 

 large, polygonal pigment cells. There is a single large axial foeding- 

 polypite which is capable of much expansion and contraction. The gas- 

 tric cells of this polypite are large and oval. Six to eight mouthless 



