47 



occasionally with the shoulders and extremities more or less brightly spotted 



with red, sides margined, extremities rather attenuated and rounded. 

 Abdomen with the pygidium exposed, pieeous or rufescent. 

 Legs rather long and slender, rufous. 



Under parts pieeous or rufescent, moderately and distinctly punctured. 

 Differs from all other sj^ecies in the attenuation of the front of the thorax, and 



generally of the extremities of the elytra. 

 Habitat, Central America. Found plentifully in Vera Paz and many parts of 



Guatemala, Mexico (Salle). 



This species is subject to much variation in colour ; some examples are black, 

 with merely the front of the thorax pellucid white or yellow, and present no vestige 

 of the medial fascia on the elytra ; while others may be described as rufescent, with 

 dark markings on the thorax and elytra ; but between these two extremes every 

 intermediate variety occurs. All these varieties are, however, perfectly consimilar 

 in form and sculpture, and may be distinguished from the other fasciated species 

 by the peculiar attenuation of the front part of the thorax ; this character is per- 

 sistent throughout the verj- extensive series of specimens collected by Mr. Champion, 

 and appears sufficient to justify the claim of S. Oberthuri to be considered a distinct 

 species. 



It is very difficult to decide with any amount of certainty between local races 

 and true species ; in Sacium, for instance, and many other genera, groups of 

 so-called species occur which bear a family likeness to each other strong enough to 

 cause a doubt as to their actual specific distinction. These may be, and probably 

 are, local forms of but one true species ; nevertheless, to regard them as species of 

 the present epoch for all descriptive or systematic purposes seems to be a course 

 less liable to error than to attempt to trace them back to some conjectural primi- 

 tive stock. 



Sacium incertum. 



S. incertum, Matthews, Biol. Centr.-Amer., Col. ii. pt. i. p. 110, 1887. 



L. c. 1"50 mm. — Ovale, modice couvexum, nitidulum, leviter et confertim 

 punctatum, pilis aureis dense vestitum, fusco-castaneum, fasciis maculisque rubris 

 variegatum ; pronoto magno, antice baud attenuato, ovaliter rotundato et modice 

 reflexo, modice et confertim punctate, interstitiis glabris, nitidis, linea basali sat 

 profunda, rufescenti, disco plus minusve obscurato, margine basali sinuata, angulis 

 rectis ; ehjtris pronoto vix latioribus, plus quam sesqui longioribus, prope humeros 

 latissimis, postice baud attenuatis, leviter et confertissime punctatis, interstitiis 

 glabris, nitidis, fusco-castaneis, fascia mediali lata, transversa, recta, macuhsque 

 rufis ad humeros atque apices variegatis, stria suturali indistincta, lateribus leviter 

 marginatis, apicibus latissimis, minime rotundatis ; pygidio rufo ; pedibus atque 

 antennis l^ete flavis, his perbrevibus. 



Body oval, moderately convex and moderately shining, finely and closely punctured, 

 thickly clothed with golden hair, fusco-castaneous, marked on the elytra with 

 a medial fascia and red spots. 



Head yellow ; eyes small ; antennae very short, bright yellow. 



Thorax large, moderately reflexed and ovally rounded, but not attenuated in front, 

 finely and closely punctured, with the interstices smooth and shining ; basal 

 line rather deep, rufescent, with the disc more or less clouded, basal margin 

 sinuated, with the angles right angles. 



Scutellum rather small, rounded. 



Elytra scarcely broader, but more than one-half longer than the thorax, widest 

 near the shoulders, not attenuated posteriorly, finely and very closely punc- 

 tured, with the interstices smooth and shining, fusco-castaneous, with a broad, 



