Harring (& Myers—Rotifer Fauna of Wisconsin — 11. 497 
glands, the form of the toes, as well as the remarkable compression 
of the neck, so striking in a dorsal view of the animal; when the 
species was first found, we assumed this to be caused by a patho¬ 
logical condition, but this was evidently an error, as it is always 
present in perfectly healthy individuals. 
CEPHALODELLA TENUIOR (Gosse). 
Plate XXXIII, figure 3. 
Diaschiza tenuior Gosse, in Hudson and Gosse, Rotifera, 1886, vol. 2, p. 81, 
pi. 22, fig. 14 .—Dixon-Nuttall and Freeman, Journ. Royal Micr. Soc., 
1903, p. 135, pi. 4, fig. 12 .—Sachse, Siisswasserfauna Deutschlands, pt. 14, 
1912, p. 123, fig. 239 .—Jakubski, Rozpr. Wiad. Muz. Dzieduszyekich, 
vol. 1, No. 3-4, 1915, p. 21 .—Weber and Montet, Cat. Invert. Suisse, pt. 
11, 1915, p. 141. 
The body is elongate, slender and nearly cylindric. The head is 
large, slightly deflexed and oblique anteriorly. The neck is not 
strongly marked. The abdomen is very nearly parallel-sided, 
slightly gibbous posteriorly; the lorica is very flexible and the 
plates indistinct; the lateral clefts are narrow anteriorly and in¬ 
crease slightly and evenly in width for about two thirds of their 
length; at this point the dorsal plates become rounded and the 
cleft widens rapidly. The foot is relatively short and broadly coni¬ 
cal ; the tail is near the end of the foot and fairly prominent. The 
toes are short, very nearly straight and parallel-sided for about 
two thirds of their length; beginning here the ventral edge curves 
upwards to meet the dorsal edge in an acute point; the length of 
the toes is one flfth of the total length. The foot glands are very 
small. 
The corona is oblique, strongly convex and without projecting 
lips. 
The mastax is large and of the normal type; the fulcrum is 
slightly expanded posteriorly and the manubria erutched. The 
gastric glands are small and occasionally have a brownish tint. 
The ganglion is very long and pyriform; eyespot and retrocere- 
bral organ are absent. 
Total length, 120~125/>i; toes 22-24jLt. 
Cephalodella tenuior is fairly common in weedy ponds every¬ 
where. It is closely related to C. forficata, from which it differs in 
the form of the toes, the much smaller size, flexible lorica and the 
form of the lateral clefts. 
