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Annals of the Transvaal Museum. 
noise : however they do not distinguish between the two species, calling 
them both “//on //on” (the sign // standing for a click, similar to that 
whic h most riders make when trying to persuade their mount to improve 
its pace). Where Ghondrodactylus was found, there also Ptenopus 
occurred. But the latter was dug from burrows of a dissimilar nature, 
generally inhabited as well by a common Namaqualand rat, Desmodillus 
auricular is. 
After rains they are said to leave their burrows, and may then be 
seen in thousands over the plains. 
In spirit this animal loses its natural colouring rapidly. In life it is ' 
brownish or greenish with black angular markings across the back : just 
behind every angular marking on each side is a conspicuous white spot ; 
below pure white. In the young the colouring is more contrasted than 
in the adult : the angular markings are darker, and between these are 
lemon-yellow bars, the rest of the back being brown and the head darker: 
the proximal half of the tail is barred with brown and yellow, the distal 
half with dark brown and white. 
Genus PTENOPUS, Gray. 
Bouleng. : B. M. Cat. I, p. 15, and Ann. S. A. Mus. V, 1910, p. 456. Werner: Rept. Ampli . 
Schnltzes Reise, 1910, p. 306. 
Ptenopus garrulus , Smith : auct. and loc. cit. 
6 examples from the Great Karas Mountains and immediate 
neighbourhood, 3024-3029. Localities : Narudas Siid, Alt Wasserfall, 
and between Dassiefontein and Noakabeb. 
Colour of these specimens for the most part light chestnut brown, 
mottled with very light brown. One individual has darker brown 
markings edged with black. The throat is aureolin. Labials 
Andrew Smith says of this species : “ Inhabits sandy districts, in the 
interior of southern Africa, is gregarious, and lives in small, nearly perpen- 
dicular burrows ; it seeks its food probably during the night, at least I 
have never seen more than its head above ground during the day” (two 
of our specimens were caught during the day in the open veld, but 
undoubtedly it is mainly nocturnal). “ In the localities in which it occurs 
many individuals may be seen peeping from their hiding places any time 
during the day, each uttering a sharp sound, somewhat like chick , chick ; 
and the number thus occupied is at times so great, and the noise so 
disagreeable as to cause the traveller to change his quarters.” 
Three of our specimens were dug out from holes in the immediate 
neighborhood of those occupied by Ghondrodactylus on the sandy plains 
near Wasserfall. 
Gen. nov. Narudasia. 
Diagnosis : digits long and slender, not dilated, strongly clawed, 
rather feebly denticulated laterally but not fringed : inferiorly with a 
series of smooth transverse plates which in places, especially in the basal 
half of the digit, are somewhat enlarged and swollen into minute pads : 
palmar surfaces with small smooth convex scales. Lower surface of the 
body covered with comparatively large imbricate scales : upper surface 
with small round juxtaposed scales of slightly varying size, those on the 
upper surface of the head being polygonal. No gular shields. No anal 
nor femoral pores. Pupil vertical. 
