CANARIAN COLEOPTERA. 115 



development and exact arrangement of its fascioe and markings, — 

 being usually paler, and also a trifle larger, in exposed barren loca- 

 lities (such as those of Lanzarote and Fuerteventura) than it is in the 

 moister and more wooded ones. In the latter indeed its blacker scales 

 often preponderate to such an extent as almost to cover the entire 

 surface, — under vrhicli circumstances a single example (if taken alone) 

 might well be mistaken for the exponent of another species. But, 

 judging from the immense series which I have collected in all the 

 islands, I am quite satisfied that no second Xenostromjylus has as yet 

 been brought to light,- — since I am able to connect completely the 

 various states, and shades of colouring, which obtain in different dis- 

 tricts. On the average, perhaps, the Canarian specimens are a trifle 

 smaller and more darkly coloured than the Madeiran ones ; and the 

 latter than those from the Mediterranean regions* : and it was to a 

 solitary and rather blackened individual collected in TeneriiFe that 

 I gave (vide ' Ins. Mad.' 127), in 1854, the trivial name oicanariensis: 

 nevertheless I now perceive, from more extensive material, that it is 

 conspecific with the X. Mstrio ; and I have accordingly suppressed it. 



Genus 80. CYBOCEPHALUS. 

 Erichson, iti Oenn. Zeitsch. v. 441 (1844). 

 The little genus CyhocejpliaJus of Erichson is undoubtedly coin- 

 cident with my Stagonomorpha (' Ins. Mad.' 484), which I regarded, 

 in 1854, as a new group of the Anisotomidce. And so closely indeed 

 do the species which compose it resemble diminutive Agathidia, that 

 it is difficult to believe that their affinities should be rather with 

 Cgllodes, Xenostrongylus, and Oychramus than with AmpliicylUs and 

 Agathidium. Still, for the reasons which have been already an- 

 nounced by Erichson, and subscribed to by others, I would not wish 

 to dispute the relationship which is usually conceded to them. Their 

 analogy, however, with the Agathidia is carried out in all their ex- 

 ternal (and many of their stnictural) details ; for not only have they 

 the power of rolling their bright glabrous bodies into a baU, but even 

 the genus itself is capable of being subdivided in a precisely similar 

 manner, dependent (as I have shown below) on the greater or less 

 oblique-truncation of the humeral angles of the elytra. Indeed this 

 loppivig-off of the shoulders would be sufficient of itself to distinguish 



* Having received from Dr. Schaum a type of the X. arcuatiis of Iviesenwetter, 

 for comparison, I may add that I am quite satisfied it is not specifically distinct 

 from the Mstrio. It is merely a trifle larger, and, from its limbs being tucked 

 under it (so as to raise up the body), has the appearance at first sight of being a 

 little more convex. 



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