1883.) Zoölogy. 429 
joint 6 and 7 taken together. Joint 6 not quite so long as 
thick; joint 7 small, conical ; broad at base where it is nearly as 
thick as the 6th; the joints rather setose; there are two terminal 
flattened sense-sete on the tip of the 7th joint. The end of the 
body is moderately blunt, with four setæ on each side of the last 
segment (anal valves). It is of a pale horn color. Length 4™™. 
is aberrant form would not at first be regarded as a Polydes- 
mus, but would be easily mistaken for a Trichepetalus. The 
individuals were mature, or nearly so, as they were horn-brown, 
In the cylindrical body and thick antennz it approaches Polydes- 
mus cavicola Pack., from a cave on the shores of the Great Salt 
lake. It differs from that species, which is eyeless, in the fusiform 
body, much thicker antennz, and the finer granulations as well 
as the larger number of segments. 
Polydesmus ocellatus > a, head i ts; 4, the ocelli; c, five ter- 
aat jon of the antennæ; d, Uae r scutes; ¢, dorsal view of 
“ee segments ; f, seven terminal segments. Highly magnified. 
THE PRIMORDIAL CONDITION OF VERTEBRATES AS SEEN IN THE 
KELETON oF THE Hoc FISH AND THE Lamprey.—A striking 
aper on the morphology of the Marsipobranchs, read by W. K. 
. before the Royal Society, is given in abstract by Nature. 
