On Snakes from N.W. Argentine and Bolivia. 457 and rapidly diminish in size towards apex. Scaling dense, variegated brown and grey, with a small but conspicuous wliite spot at the declivity on the third interval. Legs with fine grey pubescence ; intermediate tibiae curved internally just before apex, but much more markedly so in the male ; this sex also has the posterior tibias very strongly compressed laterally just before apex ; posterior tarsi with the second joint a trifle narrower than the others, second and third sub-equal, first joint very long and broad in male, longer than second and third together, but normal in female. Mashonaland : Salisbury. A plentiful species about Salisbury, usually feeding on a common herbaceous plant (^Pseudarthria sp.). It is nearly allied to vari'us, Fahr., but that species has no trace of a rostral tubercle, the elytra are more acuminate in both sexes, and the granules are obsolescent on the disk ; the interme-diate tibiae are not nearly so incurved ; and the male has the posterior tibiai and tarsi normal. The compression of the posterior tibiae in himaculatus distinguishes it from every other species in the genus known to me. LXI. — On a Collection of Snakes from North-western Argen-tine and Bolivia containing new Species. By Dr. EiNAK LONNBEKG. Baeon Eeland Noedenskiold, having returned this summer from an expedition to the Bolivian Chaco and North-western Argentine, has delivered to me for determination a collection of snakes containing sixteen species, two of which seem to be new and which I venture to describe in the following pages ; but as the region visited is very little known zoologically except through the collections brought home to Europe by I)r. Borelli*, I append the full list of species of this collection. The places where Baron E. Nordenskiold and his com-panions made the principal collections were the following : — Quinta, S. Barbara, near Laguna de la Brea, Province de Jiijuy, North-western Argentine: luxuriant subtropical forests. Moreno, Puna deJujuy, Argentine, 3500 m. above the sea-level : stony desert, with a sparse vegetation of shrubs. * Conf. Peracca; Boll. Mus. Zool. Anat. Comp. Torino, 1897, vol. xii. no. 247.