1022 Wisconsin Academy of Sciences, Arts, and Letters. 
form, from Ceylon. In 1904 Stingelin (’04) reported the 
same species from Siam and Sumatra. It is, therefore, widely 
distributed in the eastern tropics. 
In .1901 Daday described P. papuana (’01, p. 42) from 
Hew Guinea. This is a tridentata form. In 1904 Daday es¬ 
tablished the genus Parasida (’04, p. 11) for those species in¬ 
cluded under the genus Pseudosida, in which the olfactory 
setae are not placed at the end of the basal part of the 
antennule; he leaves in the genus Pseudosida of Herrick 
those species in which the sense hairs are placed at the 
end of the basal part and in which the antennule resembles in 
general that of Latonopsis. The next year he described frojn 
Paraguay two species which belong to his genus Parasida, P. 
ramosa and P. variabilis (’05, p. 218-220). 
In 1906 Stingelin (’06, p. 2) called attention for the first 
time to the fact that Herrick in his two papers had before him 
not, as he supposed, representatives of the same species but 
two different forms. Stingelin, therefore, concludes that the 
specific name tridentata is not to be rejected as a synonym but 
is to be retained and applied to a species whose antennule has 
in general the Latonopsis form. 
These are the facts regarding the genera Pseudosida and 
Parasida and they seem to warrant the following conclusions: 
1. Herrick’s genus Pseudosida 1884 was a monotypical 
genus, properly founded, and can be readily identified by 
means of his figures and description. In particular, the posi¬ 
tion of the olfactory setae on the antennule is perfectly clear 
from his figure (’84, PI. K, fig. 9,), although described in his 
text merely as “lateral” (’84, p. 20). 
2. Herrick was wrong in supposing that his form tridenta 
1887 was co-specific with bidentata 1884; and even if he sup¬ 
posed this to be the case he had no right to attempt to change 
the specific name. This is always contrary to rules of nomen¬ 
clature. In this particular case, no reason existed for de¬ 
siring the change. Herrick’s earlier sketches were carefully 
made and, as a matter of fact, showed the claws of the postab¬ 
domen correctly. There was no reason to assume that they 
were wrong, especially as any comparison of the earlier and 
