268 BULLETIN OF THE 



The axis (Ji) of ylrj. fragile is very flexilile, while the nectocalyces and scales 

 admit of more motion on each other tlian is commonly the case among Phy- 

 sophores. These a])pendages also are very transparent and small in size as 

 compared to the length of the colony. Tlie whole animal is more slender than 

 an Agalma, and the ai)pendages, in respect to their size, less conspicuous. The 

 float («) does not differ from that of other Physophores. It is relatively large, 

 and bears apical pigment-spots of crimson color. Similar colored spots are 

 likewise found at intervals along the length of the axis, especially on that 

 portion of it which bears the swimming-bells and is known as the nectostem. 

 This peculiar distribution of pigment on the stem is confined to the two species 

 Ay. 'picta and A(j. fnujilc. In other genera colored spots are found on the 

 axis, but they are not so prominent as in these two species of Agalviopsin* 



One of the main differences between the nectocalyces of Acjulmopsis and those 

 of A(juhna is the existence of three or four bright orange ocelli ((*) on the bell 

 margin near the terminus of the radial tubes. The course of these vessels in 

 the walls of the bell is almost identical in the two genera. 



The portion of the axis upon which the bracts are borne is veiy long and 

 highly flexible. The covering-scales (c) are small, inconspicuous, and trans- 

 parent. They have a rectangular shape, and are fiistened to the axis by means 

 of a short peduncle. A blindly ending, medially placed tube penetrates their 

 whole length on the inner concave surface. It opens into the stem cavity by 

 an elbow-joint. 



The polypites (_p) are long, slender, flask-shaped bodies, which are very 

 prominent on account of the network of bright crimson pigment on their 

 sides and bases. The tentacles carry tentacular knobs (PI. VI. fig. 17), which 

 have a bell-shaped involucrum and a single terminal filament without a vesicle. 

 The sacculus is tightly coiled, and has a dark red color. It bears near the 

 attachment of the involucrum a double row of prominent thread-cells. The 

 male and female bells hang in clusters from the base of the tastern (fig. 16, s), 

 and are not separated from each other on different regions of the axis. The 

 male bells (fig. 25) are smaller than the female (fig. 24) and have a crimson 

 color. The female bells are colorless. As is true of most Physophores, the 

 colony is monoecious. f 



* The tentacular knobs of Agalmopsis uiricularia, Claus, are so dilferent from 

 those of otlier PhysophoridsB that I have considered it a new genus (Bull. JIus. 

 Com)). ZoiJl., VI. 7). It may be known as Calliagahna uiricularia. 



1 In Xanomia according to Mr. Agassiz the two sexes ai-e not combined in the 

 same colony. (N. Amer. Acal., p. 208 ; Seaside Studies, &c., p. 80.) Agalmojms, 

 Agdlma, PliTjsojyhora, Athonjhia, Halistcmma, Slephaiwmia, and Praya liave both 

 male and female bells on the same stem. The same is said to be true of JLppopodlus. 

 Ahi/la, Jpokviia, and Diphycs are probably dia3cious. Sexual organs of but one kind 

 are known in Ehizophysa. They resemble those of Physalia. 



Nanomia will also be found to bear male as well as female sexual bells on the same 

 axis, as it is probably the young of Agalmopsis. My reason for regarding Kanomia 

 as the young of Agalmopsis and not of Agalma will be found in Bull. Mus. Conip. 

 Zoob, VI. 7, p. 141. 



