218 BULLETIN OF THE 
into the formation of the tentacular knob are the peduncle, the involucrum, 
the sacculus, and the terminal filament. 
The terminal filament (ft) is long, thread-like, single, arising from the 
distal end of the sacculus. In its walls are imbedded many lasso-cells, or 
nematocysts. The sacculus is closely coiled in several turns. It is a large 
reddish body, armed with batteries of lasso-cells, and crossed by prominent 
lines. Ser 
The involucrum (inv) forms a cap over the sacculus.* It is bell-shaped, 
with entire edges, the sacculus (sac) arising from the inner central point. 
The whole tentacular knot hangs from the tentacle by the peduncle. 
Tasters.{t —Among the most interesting and it would seem exceptional struc- 
tures in the genus Nanomia are those organs which are known as tasters (hf). 
The most marked peculiarity in their anatomy is the existence of an “oil 
globule” (0g) near their base. 
The tasters hang from the polyp-stem midway between the polypites. A 
single adult and many half-developed tasters occur between each pair of polyp- 
ites. Individual tasters are small, slender, flask-shaped bodies, resembling 
immature polypites. They arise directly from the stem‘ and are destitute of 
a basal peduncle. The distal extremity is closed. 
Each taster bears near its attachment a prominent red body of spherical 
shape, known as the “oil globule.” The taster has a single long tentacle (h ta), 
destitute of lateral appendages. In_the water in which Nanomia was kept 
alive, several tasters which had separated from the main stem were found 
floating about near the surface. These were not seen to grow into colonies of 
Nanomiez, but gradually became opaque and decayed, never in those studied 
growing into new colonies. 
Gonophores. — A. Agassiz supposed that separate male or female colonies of 
Nanomia were found. He considered that some colonies of this genus are all 
males, while others are all females. My observations differ in this respect 
from his. The adult Nanomia, like the genus Agalma, has male and female 
bells on one and the same colony. : 
The sexual bells (g) of Nanomia are found near the base of the tasters, 
where they form botryoidal clusters. These clusters occur on all parts of the 
polyp-stem wherever hydrocysts are found. The interior of the male bells in 
many cases has a milk-white color, while the female bells are always trans- 
parent. Each male gonophore is bell-shaped and fastened to the base of the 
cluster by a short flexible peduncle. The walls of the bell are thin, with four- 
radial tubes joined to a marginal canal. The peduncle is penetrated by a 
* The name sacculus has been given to the coiled red structure which forms 
the larger part of the knob by others. It seems more natural simply to inter- 
change the terms, so that what is now called the involucum may be known as the 
sacculus, and vice versa. 
+ The term “ taster,” used to designate these structures, is open to some objec- 
tions, but is regarded as one of the best which has been suggested to apply to these 
peculiar organs in the Physophores. 
