CAPE-VERDE GROUP. 489 



asserted habitats of which are "inore than questionable. It was 

 on this account indeed that Dohrn absolutely refused to admit 

 it (and, as I cannot but think, rightly) into his enumeration of 

 the Grastropods of the archipelago, no less than he did the Helix 

 gyrostoTna — a north-African form, likewise registered from S. 

 lago, concerning which some strange confusion seems to have been 

 brouglit about by Ferussac, who himself had previously described 

 it. If however the Ckirychium, minus has been re-detected 

 lately by MM. Bouvier and de Cessac, it is much to be regretted 

 that Morelet should not have stated this plainly, and moreover 

 let us know in what particular island (or islands) they met with 

 it. The mere insertion of a name into a geographical cata- 

 logue without any information being supplied as to the au- 

 thority on which it rests, or as to the place in which the species 

 which it represents is supposed to have been obtained, is utterly 

 insuffi^cient in cases where the most extrenae and absolute accu- 

 racy is of primary importance. 



It was in Mr. Cfray's yacht, the ' Garland,' that the islands 

 of the Cape- Verde archipelago were visited by the Eev. E. T. 

 Lowe and myself; but our two months' sojourn amongst them, 

 in January and February of 1866, was so short that we had but 

 little time (our main object being to investigate the insects and 

 plants) to devote to the Land-Shells. Still, we never failed to 

 collect them when they came in our way ; though the season was 

 so exceptionally dry, and the conditions for molluscous life were 

 so unfavourable, that we did not meet with more than 1 6 out of 

 the 41 species which are enumerated in the present catalogue. 

 And yet, through Mr. Grray's assistance and co-operation, we 

 examined, as carefully as we were able, the five principal 

 islands, — namely S. Antao, S. Vicente, S. lago, Fogo, and 

 Brava ; S. Nicolao having been explored by Messrs. Grray and 

 Lowe on a previous occasion (during February and March of 

 1864) when it was not in my power to accompany them. The 

 islands which were visited by Dohrn, in 1864 and 1865, appear 

 to have been S. Antao, S. Vicente, S. Nicolao, and S. lago ; so 

 that the three eastern ones of the Group — Sal, Boavista, and 

 Maio (known locally as the ' Salt-islands ') — would seem to have 

 been altogether untouched, as regards their fauna, until glanced 

 at lately (and, as is but too manifest, very superficially so) by 

 MM. Bouvier and de Cessac. 



Having been accustomed, in the more northern archipelagos, 

 to a great diversity in the Gastropodous list of each separate 

 island, from that which obtains in the various others, respec- 

 tively, even of the same Group, one of the first facts which 

 struck me at the Cape-Verdes was the comparative uniformity 

 ol the species throughout the cluster, — many of them, such as 



