92 Fauna Italica. 
thor " Solo in pochi punti differiscono fra loro i generi Vipera e Pe- 
lias. Laddove nel primo il capo e depresso, allargato posteriormente, 
coperto nella parte superiore di piastre o piuttosto squame conves: 
lo spigolo rostrale e risentito, prominente sull' apice del muso; il Pe- 
lias ha il capo ovale, men depresso e men sensibilmente distinto dal 
tronco, coperto superiormente di scudetti piani anzi leggermente con- 
cavi, lo spigolo rostrale non e risentito, ne rilevato aiFalto sull' apice 
del muso." Subsequently he observes of Pelias : 
" 1 inoti di queste sono in paragone men lenti ; 1'indole loro e piu 
fiera ed al solito riescono assai piu pericolose, perche, anche senza 
essere provocate, impetuosamente si slanciano e mordono." 
This would appear to be the viper of Ray and Pennant, the Colu- 
ber berus and prester of Linnaeus, C. chersea and Vipere commune 
of Cuvier , the jEsping of the Swedes, &c. &c. The number of names 
which have been collected by the Prince as synonyms of this species 
are remarkable, and we must say, not reconcilable to each other in 
all instances. The Vipere of Cuvier, for instance, does not agree with 
the reptile figured in this work. We have given the characters at 
length, in order to draw the attention of the reader to the elucida- 
tion of this genus. We strongly suspect that both Pelias and Vipera 
are to be found in this country. The writer of these observations has 
frequently killed the common viper on the moors in Northumberland, 
which is a very dark-coloured, slow and sluggish animal, moving 
from its coil when disturbed with great difficulty, and, it has always 
been found, basking in sunny dry places. On one occasion, whilst shoot- 
ing in a district upon the Reed near the Carter Fell, in a deep fern 
bed, he met with a reptile, which in colour, form, and activity, dif- 
fered so much from any he had seen before or since, that he was sa- 
tisfied it was different from the common species. It was so active 
that there was great difficulty in securing it, and it bit at the gun- 
stock with uncommon virulence, but being at the time more intent 
in the pursuit of game than on that of natural history, he neglected 
preserving it. However, it agreed in every respect with the Pelias 
berus now described, and it is mentioned for the purpose of drawing 
the attention of those who may have opportunities of attending to 
the subject. 
The common name of this animal in Italy is, Marasso palustre, to 
shew its habits of frequenting marshy districts, where it avoids the 
sun, keeping in the shade excepting in the early morning. It swims 
with great facility. It has not yet been seen south of the Apennines, 
but is found beyond the Alps. In the colouring in some of the lower 
parts there is a citrine yellow tint, which was one of the peculiarities 
