CAN AM AN GROUP. 305 



I have nevertheless shown at p. 60 of tins volume that indica- 

 tions are not wanting of certain well-marked types which do 

 nevertheless (even whilst represented by different species) per- 

 meate both archipelagos, and indeed more or less the whole of 

 them, — giving an amount of individuality to the entire pro- 

 vince, through its several component portions, which it is 

 impossible not to recognize. Thus, to compare our present 

 cluster with that of the Madeiras, we see (even amongst the 

 forms which may be said to be ' characteristic ') the sections 

 Vermetum (of Hyalina), Janulus (of Patula), and Mitra, 

 Irus, Spirorbula and Discula (of Helix), as well as the genus 

 Lovea (allied to Achatina) and Craspedopoma (allied to Gy- 

 clostoma), cropping up, under specifically distinct exponents, 

 in them both* And yet, in spite of this, I also called attention 

 to the circumstance that the unity of this whole Atlantic region, 

 so clearly shadowed forth, is nevertheless immeasurably over- 

 balanced by the marvellous isolation (the evidence for which is 

 even still more pronounced) of its several parts. But what 

 may be the exact bearing of all this upon the existing geogra- 

 phical phenomena I will not venture to suggest, — the possible 

 breaking-up (at an exceedingly remote epoch) of a more or less 

 continuous land, which had been colonized along circuitous 

 ridges, now lost beneath the ocean but connecting one or the 

 other of its various portions, being but a single explanation out 

 of many, and entering into the province, whatsoever be its plausi- 

 bility, of mere conjecture. 



Had we only the Land-shells from which to judge, this unity 

 of the so-called ' Atlantic province,' although (I think), even 

 Helicologically quite unmistakeable, would perhaps have been 

 less positively insisted upon, in my present remarks, than it is ; 

 but with the Coleopterous statistics likewise before me, on 

 which to build up an independent judgment, I must plead 

 guilty to a very full appreciation of the few conchological facts 

 which would seem to bear on the ' individuality ' (as I have ven- 

 tured to express it) of the entire region. I do not, however, 

 feel it necessary to apologise for this slight a priori bias, — 

 because, our sole object being to arrive at the truth, we ought 

 to be thankful, rather than otherwise, for any extraneous evi- 



pusilla, Lowe ; the Helix jiavpercula, Lowe ; the Pupa microspora, Lowe ; 

 the ' 6. anconostoma,'' of the P. umbilicata, Drap., and the P. fanalensis, Lowe, 

 and the Lovea tornatellina, Lowe. Mousson mentions that there are but 

 three species thus circumstanced, — namely, the Helix paupercula, the Pupa 

 microspora, and the P. anconostoma ; but that arose principally from his not 

 having been aware (1) that the Patula servilis, Shuttlw., is identical with 

 the pvsilla, Lowe; (2) that Lowe's ' pusilla, var. j8. sericma,' is Shuttle worth's 

 P. placida ; and (3) that his own Pupa debilis is conspecific with the P. 

 fanalensis of Lowe. 



X 



