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tional interest in connexion with that ancient continent, 

 of which these ocean ruins, on which for so many ages it 

 has been cut off, are the undoubted witnesses. Approxi- 

 mating in affinity to Parmena and Dorcadion, yet pre- 

 senting a modification essentially its own, it becomes 

 doubly important in a geographical point of view ; and 

 it was therefore with the greater pleasure that I lately 

 received a second representative, from the distant rocks 

 of the Salvages, midway between Madeira and the 

 Canaries. Differing widely in specific minutiae, yet 

 agreeing to an identity in everything generic, they offer 

 conjointly the strongest presumptive evidence to the 

 quondam existence of many subsidiary links (long since 

 lost, and radiating in all probability from some interme- 

 diate type) during the period when the whole of these 

 islands were portions, and perhaps very elevated ones, of 

 a vast continuous land. ***** The Deucalion 

 Desertarum is of the utmost rarity, the only two* speci- 



its subconnate elytra, and its attachment (at any rate in the larva 

 state) to the interior of the stems of particular, local plants, or its 

 retiring propensities within the crevices of rocks; we are at once 

 struck with the conviction, that, during the enormous interval of 

 time which has elapsed since the mighty convulsions which rent 

 asunder these regions terminated, it has probably never removed 

 many yards from the weather-beaten ledges which it now inhabits." 

 * Since the above was published, I have succeeded in detecting 

 one more example, namely (in June 1855) on the summit of the 

 Ilheo Bugio, or Southern Dezerta, within a few yards of the self- 

 same spot where it was found by the Rev. R. T. Lowe in May 1850. 

 Although I searched diligently on the Dezerta Grande, during my 

 late campaign in the Madeira Islands, I was not able (so great is 

 its rarity) to discover farther traces of it on that rock. 



