370 Mr. J. Blackwall on newly discovered Spiders 
me to the same effect, he having seen this fossil. The animal, 
of which the head is wanting, is abundantly endowed with 
feathers. It possesses a long tail, like Rhamphorhynchus, and a 
small pelvis; like birds, it has a single bone forming the tarsus; 
it is furnished with three toes ; on the anterior limbs there is a fan 
of feathers, and also on the tail, on which the feathers radiate, not 
from the last vertebra, but laterally along the vertebre. The 
simple tarsus of itself shows that this animal does not belong to 
the Pterodactyles, and the formation of the tail contradicts the 
idea that we connect with our birds, yet the feathers are not 
distinguishable from those of birds. The fossil feather from 
Solenhofen described by me will be derived from a similar ani- 
mal, for which I have selected the name of Archeopteryax litho- 
graphica*, 
XLI.—Descriptions of newly discovered Spiders from the Island of 
Madeira. By Joun Buackwa tt, F.L.S. 
A cottection of Spiders recently made in the Island of Ma- 
deira, and presented to me by the Rev. Hamlet Clark, comprised 
the following species, which appear to be new or imperfectly 
known to arachnologists. 
Tribe Octonoculina. 
Family THomisip&. 
Genus THomisus, Walck. 
Thomisus spinifer. 
Length of the male 4th of an inch; length of a cephalo- 
thorax ;4;; breadth 75; breadth of the abdomen 203 length of 
an anterior leg +; length of a leg of the third pair 3 
The cephalothorax is broad, convex, glossy, slightly core 
before, rounded in front and onthe sides, abruptly depressed at 
the base, provided with a few strong black bristles, those on the 
frontal margin being directed forwards, and is of a reddish-yel- 
low colour, an obscure band in the middle, which tapers from 
the eyes to its posterior extremity, being the palest. The eyes, 
which are seated on whitish spots, are disposed on the anterior 
part of the cephalothorax in two transverse curved rows, forming 
a crescent whose convexity is directed forwards ; the eyes of each 
lateral pair are placed on tubercles, those of the anterior row 
being the largest of the eight. The falces are short, cuneiform, 
and vertical; the maxille are obliquely truncated at the extre- 
mity on the outer side, and inclined towards the lip, which is 
triangular; the sternum is heart-shaped; the legs are very un- 
* Jahrb. fiir Mineral. 1861, p. 679. 
