Mr. T. V. Wollaston on undescribed Madeiran Insects. 19 



of Madeira proper and the Dezertas (as well as to the greater 

 opacity of its male sex, and the more shining surface of the 

 feniah'), — it is not until now tliat I have ventured to rci^ard it 

 as specitieally distinct; and it is througli the detection by Mr. 

 Janson of a good, structural character, which cannot possibly be 

 the result of any combination of local influences to which it may 

 have been long exposed in the more remote island of Porto 

 Santo, that I would without hesitation, in the present paper, 

 propose for it a new name. The peculiarity above alluded to 

 (to which Mr. Janson has lately directed my attention) is a most 

 remarkable one; nevertheless it had entirely escaped my own 

 observation hitherto. It consists in the fact of the four hinder 

 tibiae of the males being densely fringed with long and very 

 robust hairs along the apical two-thirds of their inner edge. It 

 is a character which is most anomalous for the Caluthi, and one 

 which cannot fail therefore to strike every Coleopterist as abun- 

 dantly sufficient, even of itself, to establish a specific claim ; but 

 when it is viewed in conjunction with the other differences, of 

 outline and form, long ago alluded to, the C. finibriatus may be 

 at once looked upon as a most interesting addition to the 

 Geodephaga of the Madeiran group. And I may add, moreover, 

 that it is a most important consideration (and one which tends 

 directly to substantiate the validity of other species, somewhat 

 similarly circumstanced, and concerning which I have expressed 

 occasional doubt, — such as, for instance, t\\e. Hadrus illutus), that 

 so abundant and universal an insect as is the C. complanatus 

 throughout jMadeira proper and the Dezertas, should have a 

 strictly representative species, and equally common, in the more 

 distant island of Porto Santo. 



Genus Trechus, Clairv. 

 Trechus Jansonianus. 



T. subovato-oblongus, angustatus, fusco-piceus, nitldus ; prothorace 

 parvo, subcordato, ia disco paruin convexo, liasi utriiiqne leviter 

 impresso, angulis ])Ostieis subrotuudatis ; elytris abbrtn iatis (pvgi- 

 dio multo brevioribus), lajvibus (striarum fere carentibns), versus 

 latera necaon ante apiccm paulo dilutioribus ; aateaais testaceis, 

 brcviusculis, valde robustis ; pedibus palhdo-testaceis. — Long, 

 corp. I3 lin. 



Several specimens of the present very interesting little Trechus 

 were discovered by Mr. Janson (to whom I have dedicated the 

 species) amongst the refuse which had accumulated around some 

 blocks of a trunk of a Dragon-tree brought from Madeira proper 

 by ]Mr. Mason. In general affinity (and probably also in habits) 

 it is closely allied to the T. finicola; nevertheless it is altogether 



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