20 INSECTA MADERENSIA. 



near the upper extemity of the Boa Ventura : and in May 1850 I again detected it, 

 beneath logs of wood, at the edges of the Levada of the Ribeu-o Frio ; and dui'ing 

 my encampment in the lofty uplands of the Cruzinhas and the Fanal, in July of 

 the same year, I obtained several specimens from beneath dead leaves and under 

 the decaying trimks of trees with which those remote forest regions everywhere 

 aboiind. 



Genus 8. EURYGNATHUS, WoU. (Tab. I. fig. 1 et 3.) 



Corpus magnum, oblongo-ovatum, depressum, Licino affine : capita magno, in fceminis latiore et ple- 

 rumque maximo : prothorace subquadrato : ehjtris connatis : alls nullis. Antenrue filiformes, 

 capite prothoraceque vix breviores, articulo primo robusto, secundo brevi, tei-tii apice et sequen- 

 tibus pilosis. Labrum (I. 1 a, et I. 3 a) transversum, anticc setosum integrum. Mandibula 

 validffi latfe robustse crassae obtusissimae, superficie superiore insequali, intus baud dentatse. 

 Maxilla (I. 3 b) bilobae, breves : lobo externa palpiformi biarticulato : interna flexuoso, parum 

 obtuso, intus valde ciliato. Palpi articulo pcnultimo elongato, ultimo subsecuriformi-truncato. 

 Mentum (I. 3 c) transversum, antice profuude emarginatum et dente medio nullo instructum. 

 Ligula ampla elongato-quadrata, apice integra ; paraglossis ei aqualibus. Pedes elongati, vix 

 robusti : tarsis aniicis in maribus (I. 1 b) articulis primo et secundo valde dilatatis (illo elongato- 

 subquadrato, hoc breviore transverso-quadrato), tertio quartoque parvis ; ultimo in omnibus 

 elongato subelavato : ungidculis simplicibus. 



A €vpv<; latus, et yvddo^ mandibulum. 



The singular insect, so abundant in Porto Santo, from which the above diagnosis 

 has been di'a^vn, ymtglit prima facie be mistaken for a gigantic Licinus ; neverthe- 

 less a closer inspection will at once show that it possesses many important distinc- 

 tions which must tend to separate it altogether from that genus. Thus, for 

 instance, its mandibles are extremely broad, obtuse, and thick, -n-ithout any appear- 

 ance of teeth internally ; its upper lip, unlike that of Licimts, is perfectly entii-e ; 

 its ligula is more elongated ; and its inner maxillary lobe is short, and blunt at 

 the apex. Its greatest pecidiarities, however, arc unquestionably external ones, 

 for, in addition to its apterous body and connate elji;ra (in both of which respects 

 it recedes from Licimis), it presents a most anomalous character, — and one un- 

 paralleled in any other Coleopterous form "with wliich I am acquainted, — in the fact 

 that the females have the head usually greatly developed and broad, wliilst in the 

 males it is comparatively narrow and small. So unusual a circumstance as this 

 led me to suppose, before I had seen the insect in suificieut profusion, that there 

 were two distinct species, and that I had only obtained one sex of each : Init diu-ing 

 my residence in the island of Porto Santo, in the ^\'inter of 1818, I had an oppor- 

 tunity not only of obser-vdng them in situ, but also in coitu ; and of remarking 

 likewise, from the examination of many hunchvd specimens, that the (Ulatcd tarsi 

 (the essential characteristic of the males) invariably accompanied tlie small heads, 

 — and vice versa. It was not, however, in every instance that the heads of the 

 females were largely developed; nevertheless the tendency to become so was 



