SAXINIS. 89 
fourth outwardly, the basal joint metallic bluish, the third joint fulvous ; thorax one third broader than 
long in the male, distinctly broader in the female, very closely and distinctly punctured on the disc, a 
little more strongly but less closely so at the sides, the anterior margin strongly produced at the middle ; 
elytra with closely approached rows of rather deep punctures, the interstices also closely and finely 
punctured and more or less transversely rugose. . 
Hab. Mexico, Northern Sonora (Morrison), Juquila, Oaxaca, La Parada (Sal/é). 
I cannot treat S. sonorensis as a variety of S. guadrina or refer it to any of the 
species described by Lacordaire, the fifteen specimens received being constant in the 
above-mentioned particulars. The insect averages larger in size than S. guadrina, and 
is of a bluish-green colour. The thorax instead of being very finely and rather 
remotely punctured is very closely and much more strongly punctate on the disc. 
The elytra are very differently punctured to those of S. guadrina, the punctures being 
so closely arranged below each other as to form almost continuous striz, and the inter- 
stices are also closely but finely punctured ; and the humeral spot (which in S. guadrina 
is quadrate) has its posterior margin rounded—it extends inwards to half the width 
and downwards to not quite half the elytral length. A certain number of specimens, 
also obtained in Northern Sonora, differ from the type in the much less closely 
punctured thorax, and in the rather smaller red humeral spot; but I cannot find any 
other characters of importance by which to separate them (they may still be distin- 
guished from S. guadrina by the dark bluish or greenish colour, and the punctuation 
of the elytra and their more rounded red spot). The other Mexican examples agree in 
the punctuation of the thorax and in that of the elytra, but they differ in the form of 
the humeral spot (this being shaped as in S. quadrina) ; it is therefore impossible 
to say with certainty whether these specimens represent another closely allied species 
or a variety of S. sonorensis, the latter being the most probable. 
2 (s). Saxinis irregularis. 
Metallic dark blue; thorax shining, rather remotely punctured; elytra strongly and irregularly punctured 
anteriorly, each with a subquadrate fulvous humeral spot. 
Length 14 line. 
Hab. Mexico, Ciudad in Durango (Forrer). 
The thorax in this species is not closely and rather evenly punctured throughout, 
very shining, and of a metallic dark blue colour; it is about one half broader than 
long, but more transverse in the female. The scutellum is closely and strongly 
punctured. The elytra are very strongly and closely punctured, the punctures being 
all of similar size and not intermixed with smaller ones and scarcely showing a trace of 
a linear arrangement ; this punctuation extends also to the fulvous humeral spot, the 
latter being similar in shape to that of S. guadrina. S. irregularis is therefore 
principally distinguished amongst its allies by the punctuation of the thorax being remote 
and that of the elytra irregular ; in most of its congeners the thorax is more closely 
punctured at the sides than on the disc, which in the present insect is not the case. 
BIOL. CENTR.-AMER., Coleopt., Vol. VI. Pt. 1, Suppl., Aprid 1889. n 
