252 MR. C. L. MARTIN ON ECHINOPS, 
they may also become paler with age. It will be observed, however, I only urge it as 
a probability that the two animals are specifically identical. With regard to the affini- 
ties of Echinops, I shall endeavour to illustrate them by a comparison of the characters 
of the genus with those of Centetes, Erinaceus, and Hriculus. 
In the form of the true molars there is a close agreement between Centetes and 
Echinops, as well as in the number of these teeth ; still other characters of the dental 
system clearly separate between these two genera, independently of such as are purely 
external. In Centetes (at least in the species Centetes setosus) the incisors above are 
four, small and pointed ; below six, minute ; in each jaw, separated by an interval from 
the rest, are two long compressed pointed canines ; after a considerable interval follow 
on each side, above and below, two false molars, the second the largest ; to these suc- 
ceed four true molars, with triangular crowns. Still more distinct is the dental system 
of Echinops from that of Erinaceus, close as is the alliance between them in all external 
characters. In Echinops, for example, as in Erinaceus, the feet have five toes ; the 
inner toe of the fore-feet is small and seated on the wrist, the other toes are small, and 
armed with feeble, compressed, hooked claws, the last toe the smallest : the toes of the 
hind-feet resemble those of the fore-feet, and the inner and outer are the smallest. The 
snout, ears, tail, and spiny covering of the upper surface of the body, are also alike in 
both. In Erinaceus, however, the upper incisors are six; there are no canines, but 
three false molars on each side, and four true molars, of which the last is small and 
narrow ; the others square, with two outer and two inner tubercles ; while in the lower 
jaw, the incisors, two in number, are very large, followed on each side by three false 
molars and four true molars. 
In Echinops the teeth are thirty-two in number. In the upper jaw the incisors are 
four in number, and apart; the two middle are large, sub-cylindrical, elongated, and 
placed at the apex of the jaw; the two others are small, and seated behind the former. 
Separated from these by a small space, succeeds on each side a tooth, which, from its 
situation and magnitude, I am inclined to regard as a canine ; it is similar in character 
to the incisors, but is stouter, and has a slight posterior notch. The molars are five on 
each side: of these the first is false and simple; the three next are transversely elon- 
gated, with two external tubercles in contact, and one internal; hence their crowns as- 
sume the form of an elongated triangle, the apex being internal; the fifth molar is a 
slender lamina, placed transversely, but not advancing so far laterally as the molar pre- 
ceding it. The under jaw presents four incisors, the two middle being very small, 
somewhat apart from each other, and directed obliquely forwards: immediately behind 
the incisors below, on each side, without any interval, there follow in succession two 
larger and conical teeth, of which the first, from its situation, may be regarded as a 
canine ; the second is the largest, and constitutes a false molar. The outermost incisor 
on each side (below) the canine, and the false molar agree with each other in form, and 
are set together without any interval, all leaning obliquely forwards. Separated from 
