PART IN—THE SUBGENUS CYCLOSALPA, 
By Wrti1Am KEITH Brooks. 
The subgenus Cyclosalpa, including S. pinnata, S. affinis, S. virgula, and 
S. floridana, is well marked, and distinguished from other salpas by many 
structural characteristics. The subgenus owes its name to the shape of the 
colony of the aggregated form, which is a wheel or rosette, as is shown in 
figures 8 and 9, plate 2. 
Three of the four known species of Cyclosalpa—sS. pinnata, S. affinis and 
S. floridana—have in the solitary form, 
peculiar luminous organs. No luminous 
organs are described in S. virgula, and I 
have had no opportunity to study this 
species. It is not impossible that these 
organs will be found to be present in this 
as in the other cyclosalpas. In S. pinnata 
the luminous organs are present in the 
aggregated form as well as in the solitary 
form. In the other species they seem to be 
restricted to the solitary form. 
One of the most notable of the common 
characteristics of the cyclosalpas is the in- 
testine of the solitary form. This is long 
and runs upward and forward from the 
ventral stomach to open into the cloaca or 
median atrium on the dorsal side of the 
body a little posterior to the ganglion. It 
lies in that part of the body-cavity which is 
included in the so-called gill. 
Plate xxxv of my memoir on “ The Genus Salpa” is a median longi- 
tudinal section of an advanced embryo of S. pinnata, showing the gill, g, 
between the pharynx, which is colored red, and the cloaca, which is colored 
green. The intestine, p, is shown in its place in the cavity of the gill, while 
the anus, p’, opens into the cloaca. The relation of the intestine to the gill 
is also shown in S. pinnata in figures 1, 2, and 3 of this memoir. Figure 7 
of plate 2 of this memoir is a side view of an advanced embryo of S. flori- 
dana, showing that the relation of the intestine to the gill is the same as it 
is in the other cyclosalpas. 
EO 
mle 
Fic. 1—The solitary Salpa pin- 
nata in ventral view. 
81 
