132 
DIPLOPODA. 
because the other known Central-American representatives have the body less elevated 
and 
compressed and the keels rather larger and less vertical than the typical form from 
Flores, and thus bridge over the interval, to a certain extent, between the latter and 
the 
larger species here described as L. laminatus. 
Key to the Species. 
a. Larger (11 mm. long and nearly 3 mm. wide). Keels widely extended and lami- 
nate, those of the 19th as broad as the tergal plate of the 20th and extending 
nearly as far backwards. . 1. 1. 1 ew eee ee ee ew ee Laminatus. 
a’. Smaller (not over 9 mm. long and about 1°5 mm. wide). Keels smaller, less 
b. 
ob 
extended, those of the second segment larger than those of the rest of the body ; 
of the 19th smaller than the tergal plate of the 20th and not extending nearly 
so far backwards. 
Antero-lateral lobe of the keels extending only a little beyond the level of the 
postero-lateral lobe, lobe on the posterior border defined by a deep notch. . celatus. 
. Antero-lateral lobe of keels extending well beyond the level of the postero- 
lateral lobe ; the lobe on the posterior border not defined by a deep notch . perparvus. 
1. Lophodesmus laminatus, sp. n. (Tab. X. figg. 1-14.) 
3. Colour: upper surface a uniform blackish-brown ; legs, antenne, head (except forehead) testaccous. 
Head punctured, the forehead furnished with a coarsely and closely granular patch. Antenne short and 
thick, the fifth segment much the longest and thickest, the sixth very short. The whole of the dorsal 
surface covered with tubercles or granules. The keels depressed, covering the legs, continuous. The 
crest of the first projecting far beyond the head, with border convex and divided into 10 lobules and 
marked above with 9 sulci, which radiate backwards from the border. ‘The upper surface of each segment 
furnished with two rows of large pointed tubercles, each row consisting of three tubercles, or rarely of 
two, when the posterior two unite. The keels projecting at right angles to the long axis of the body; 
their anterior and posterior borders parallel to each other and lying respectively in the same straight 
line with the anterior and posterior borders of the tergite; the anterior border furnished proximally with 
three rounded tubercles, distally entire, with a marginal sulcus, the anterior angle completely rounded, 
the lateral margin with a single deep notch prolonged into a groove; the posterior angle also rounded, 
but trilobate on the poriferous segments, the median lobe elongate, supporting the pore; the posterior 
border marked with three distinct notches which are prolonged into sulci on the dorsal surface and divide 
it into three lobes. Anal tergite wide, laminate, divided by four notches into five lobes, of which the 
median is itself bifid. Sterna narrow, sulcate. Leys thick ; trochanter more than half the length of 
the femur. 
Phallopods consisting of a pair of stout, convex, dome-shaped, basal segments, rounded outside, hollow within, 
in contact in the middle line and diverging from each other and possibly capable of being closed; the 
hollow of each facing that of the other and containing the distal portion of the organ, which fills the 
cavity and is in contact with that of the opposite side. Each consisting apparently of a single stout 
sclerite, which from its anterior aspect is seen to be deeply sulcate and to be bilobed apically, the external 
lobe more projecting than the internal; the former, when viewed from below, appears a rounded boss 
connected by a ridge with the smaller and lower internal lobe; when viewed from behind there is seen 
to bea crest, in contact with that of the opposite side, running vertically down the sclerite and terminating 
in a slight hook-like process. The posterior margin of the hollow formed by the proximal segment 
bears numerous stiff sete. Legs of the third pair much thickened in the region of third segment. 
Sterna of the fifth segment with a median projection. 
Length 11 millim., width 2°38. 
Hab. Mexico, 'Teapa in Tabasco (H. H. Snvith). 
