1897.] Zoology. 539 
somewhat club-shaped without any adoral cilia for some distance, but 
with the single, larger cilium (e, No. 2, above) and a group of rather 
crowded, short, fine cilia on the back. Later, both were of normal 
form, and again, two days later, the same club-formation was noticed 
on one of them. These were the only instances where this form w 
seen, and it is impossible to judge, at present, whether it was an inci- 
dental, abnormal formation, or one occurring regularly during growth ; 
yet the former is more probable. 
There is one somewhat peculiar and interesting feature about the 
fission in our species: In almost all other ciliates the two newly formed 
individuals are of about equal value, even in the Peritricha. In Stich- 
ospira the anterior animal evidently leaves as soon as separated, while 
the posterior remains in place in its dwelling. Here, then, fission 
seems to approach, in a certain degree, gemmation. 
Several times specimens were seen free and contracted in the shape 
shown in fig. 3. Whether they were anterior individuals formed by 
fission, or such that had been thrown out of their cavities, accidentally, 
remained in doubt. Both assumptions may be true. On such animals 
a few cilia, of common form, were seen near the posterior end of the 
body (see No. 12, above, and fig. 3, cp). 
From the description and figures it is apparent that Stichospira is a 
ciliate of very peculiar organization. In the formation of its anterior 
part it resembles the Oxytrichids, with which it is to be ranged, but 
representing a group of its own, owing to the formation of its middle 
and posterior parts and the mode of life. With the latter moments it 
resembles, to a certain degree, some heterotrichous and peritrichous 
ciliates. It may also be said that the highly differentiated apparatus 
of cilia in the anterior are in a strange contrast with the simple, sack- 
like posterior part produced by and adapted to the animals’s living in 
a cavity or tube; that is to say, for a form of Oxytrichide, And in this 
connection, the situation of the anus, in the anterior part of the body, 
is also very significant. This is an exceedingly illustrative example, 
and rare to such a degree among ciliates, of the mutual impressions of 
organization and mode of life. 
It must be added, however, that the organism under consideration is 
not without its analogies and homologies. On the one hand, it has 
much in common with Freya, and in a similar way with Amphileptus, 
etc., by the forward extension of the anterior part with the adoral zone in 
front of the peristome. On the other, it is nearly related with Stichotricha 
acuminata Pty., for which species the first examples seen were errone- 
ously taken, and in allusion to which the generic name was given to our 
