248 BRITISH SERPENTS. 
men was sent to me by the Rev. C. Davies, Cenarth, 
Caermarthenshire, for identification. It turned out to 
be a variety of the adder known as the “ black adder” 
(the Coluber prester of some writings). This specimen 
was a female 202 inches long, and is the first recorded 
in this part of the country. Still more interesting 
is the fact, which I have since ascertained, that the 
black adder is not uncommon in the neighbourhood of 
Cenarth, though but rarely killed on account of the 
great dread the inhabitants have of its danger. There 
are two specimens in the South Kensington Museum 
taken in this country, and a considerable number from 
the island of Seeland, where they seem fairly common. 
G. A. Boulenger has given special attention to the pro- 
duction of the melanism which he described in the 
‘Zoologist’ of February 1895. He has shown that the 
black colour is produced differently in the two sexes: 
in the males by the expansion of the black markings, 
in the females by “a gradual darkening of the ground 
colour.” 
VII. North Wales Province. 
Vipera berus.—The distribution im this province is 
very irregular, common in some places, in others the 
adder is apparently absent. 
Tropidonotus natria.—This species is generally dis- 
fo) 
tributed in North Wales, in some places growing to a 
large average size. 
