AMPLINUS. 153 
Polydesmus (Euryurus) erichsonii, Peters, Mon. Ak. Wiss. Berlin, 1864, p. 542°. 
Pachyurus erichsoni, Attems, Denk. Akad. Wien, Ixviii. p. 288 (1900) °. 
Hab. Mexico !~* (Deppe). 
This species, although the type was said by Peters to be in the Berlin Museum, does 
not appear to have been examined or described since the days of Brandt. Judging 
from the original description, A. erichsoni is very closely allied to A. Alugi, and since 
the type-specimens of the two were obtained in Mexico by the same collector, it is not 
improbable that they belong in reality to the same species. 
8. Amplinus armatus, sp.n. (Tab. XI. figg. 6-6 4.) 
2. Colour of dry specimen a uniform chocolate-brown, with the legs and antenne flavous. Sculpturing of 
dorsal area of mid-region of body consisting of three rows of polygonal areas roughened with granules and 
each bearing a rounded tubercle. At the posterior end of the body the segments become more regularly 
covered with rounded and elongate tubercles showing no definite arrangement, the polygonal areas 
being obscured; dorsal area of the 19th segment uniformly covered. First tergal plate showing very 
definite areas, which are smooth in its middle third and granular at the sides; on the second and third 
the sculpturing consists of large smooth tubercles in the middle, arranged in three rows, and of granules 
and much smaller tubercles at the sides and on the keels. eels large; those of the mid-region of the 
body with the anterior angle nearly rectangular and toothed; lateral border of all the keels, except those 
of the Ist and 19th segments, distinctly but irregularly toothed ; the teeth smallest on the anterior and 
posterior keels ; the anterior border lightly convex, the posterior lightly concave; the posterior angle 
acute and pointed; the marginal thickening well-developed, even on the 2nd and 3rd keels, which have 
somewhat strongly convex anterior border, correspondingly concave posterior border, obtuse anterior and 
acute posterior angle. Cuudal process of anal segment squared with straight sides, subrectangular 
angles, and lightly convex, lobulated posterior border. Anal sternal plate emarginate, the tubercles 
on rounded prominences, 
Length of 9 75 millim., width 12. 
Hab. Mexico (Mus. Brit.). 
A single female specimen in the collection of the British Museum. 
Nearly related to A. klugi, Brandt, but differing in having the anterior margins of 
the keels more squared and the lateral margins manifestly denticulated, those of the 
pore-bearing segments straight and less bulging, and the posterior angles of the second 
and third more acute. Male unknown. 
9. Amplinus triramus, sp.n. (Tab. XI. figg. 7-74.) 
Colour varying through all shades from dark chocolate-brown to testaceous ; at most the thickened borders of 
the keels yellowish in dark specimens, but these almost always of very much the same tint as the rest 
of the dorsal surface ; antennz yellow, with terminal segments brownish ; legs and ventral surface yellow. 
The whole of the dorsal surface of the metazonites covered with shining tubercles, which commonly 
stand up near the centre of irregularly granular areas defined by sulci and evidently representing the 
polygonal areas seen in the previously described species of this genus and in those of Polylepiscus. 
The tubercles vary in size and shape, being more elongate in the middle of the back and becoming more 
spherical upon the sides and on the upper surface of the keels. First tergal plate convex, covered 
with rounded tubercles and granules, with a series of elongate tubercles along the median portion of its 
posterior border; the lateral angles produced, but blunt, with a lightly emarginate anterior border. 
BIOL. CENTR.-AMER., Diplop., December 1909. x 
