PHOTINUS. 39 
Equal in size to P. congruus; the form of the prothorax is different, being longer, 
more narrowed in front, and not so wide at the base, from which the sides begin to 
contract at once, forming acute angles with the base. There is a rather indistinct 
carina on the front half of the disk. ‘The elytra are much darker and more ovate than 
in P. congruus, the pale vittz are only a little visible in paler specimens, they have the 
lateral margin expanded, two nervures a little visible near the base, and are clothed 
with a grey, but very short pubescence. The pygidium in the male is truncate, the 
seventh ventral plate with a round emargination, fuscous in the middle, diaphanous at 
the sides. In the female the apical plate is dark fuscous, notched, the penultimate 
dark at its base. 
3. Photinus gliscens. (Tab. IV. fig. 13.) 
Pallide testaceus; capite, antennis, palpis, genibus tarsisque nigro-fuscis; prothoracis disco aurantiaco, 
macula obconica picea, obsolete longitudinaliter impressa; elytris subparallelis, fuscis, margine externo, 
sutura et vitta discoidali sat lata pallide testaceis. Long. 18 millim. ¢ 9. 
Hab. Muxico, Tuxtla (Saldé). 
This is one of the most conspicuously marked and handsomest of the Photini, and 
is very distinct from any other known to me. ‘The head is fuscous, excepting the 
mouth and antenniferous tubercles. ‘The antenne and palpi fuscous. ‘The whole of the 
underside in the male is pale, excepting the base of the first four ventral plates, which 
are irregularly blotched with fuscous. In the female, as usual, the breast and all the 
segments are more or less of the darker colour, the paler parts being the margins of 
the first four, the middle of the fifth, and the whole of the apical one. The thorax 
is nearly semicircular; but the base is a little contracted; the disk bears a rather 
long triangular spot, the apex of which is towards the base. The elytra are dark 
fuscous, with conspicuously pale margins and central vitta. The male has the 
pygidium with a double notch. The female the same, very slightly sinuate; the 
ventral plate rounded, and with a minute emargination in the centre. 
4, Photinus nigridorsis. (Tab. IV. fig. 17, 2.) 
Nigro-fumosus, elytris subopacis, oblongo-ovalis, prothorace antice angustato lateribus late testaceis, elytris 
marginibus et apice indeterminate late testaceis. Long. 13-15 millim. g 9. 
Hab. Mexico, Istapan, Juquila (Sallé, Mus. J. Sturm). 
A female specimen from Juquila is figured in the Plate. 
Body beneath, legs, and antenne smoky black ; in the male the seventh and apical 
ventral plates and the apical half and margins of the pygidium are pale; in the female 
the apex only. The antenne are subfiliform, longer in the male and a little com- 
pressed ; the eyes of moderate size, larger in the males than the females. The thorax 
is wider at the base than long, the sides sinuous and not much reflexed. The disk is 
almost smooth, in some a faintly impressed channel, in others a very fine carina may 
