558 TEST ACE A ATLANTICA. 



Habitat in intermediis ac subelevatis insulse, et recens et 

 semifossilis. Species statura et soliditate valde inconstans, 

 sc. in locis humidis plerumque major fortiusque colorata, sed in 

 aridis inferioribus minor, multo fragilior, pallidior, et ssepe 

 indumento lutoso vestita. 



After a very careful comparison of a vast array of Succineas 

 from many different parts of the island (chiefly, however, of an 

 intermediate altitude), I have come to the conclusion that it is 

 quite impossible, despite the opposite appearance of their ex- 

 tremes^ to uphold any of them as specifically distinct from the 

 remainder ; though I believe that they have been quoted, in 

 isolated papers and monographs, under at least five or six dif- 

 ferent names, if not more. The fact is, the examples from 

 nearly every locality seem to have some . little feature of their 

 own, mere size and solidity, within certain reasonable limits, 

 and the greater or less development of the subapical whorls (and 

 the consequent length of the spire), as specific characters, 

 counting absolutely for nothing. Indeed so completely do the 

 many phases of this Protean shell merge imperceptibly into each 

 other that it is scarcely practicable to treat any of them as even, 

 definite and well-marked ' varieties ' ; and I can only mention, 

 therefore, in a broad and general way, that specimens from dis- 

 tricts which are much dried up, and denuded of their original 

 wood, are smaller, and thinner in substance, as well as paler in 

 hue, than those from damper and more elevated ones where the 

 shell has been more perfectly matured, and that they have also 

 a greater tendency to coat themselves over (as though to com- 

 pensate for the deficiency in substance) with a hardened enve- 

 lope of dirt. 



Examples in this latter condition will sometimes adhere to 

 the faces of the rocks, their additional covering appearing not 

 only to defend them from the rays of the sun, but likewise to 

 conceal them from the depredations of the St. Helena plover, or 

 'Wire-Bird' (jEgialitis 8anctce-Helence, Harting), which is 

 very partial to them as food. This is expressly alluded to by 

 Mr. Melliss, who has informed me that individuals of the latter 

 which were obtained by himself and Mr. E. L. Layard at New 

 Ground (below Plantation) were observed, on being opened, to 

 have their crops filled with examples of this small race of the 

 Succinea. I cannot agree with him however in quoting that 

 particular phasis of the shell under a distinct title ; and still 

 less could I affiliate 4t with the ' S. solidula ' of Pfeiffer, be- 

 cause on referring to Pfeiffer's original diagnosis of the latter, 

 which was drawn-out from a specimen in the collection of the 

 late Mr. Cuming, I find that he was absolutely ignorant of the 

 country from whence it came, and that there is consequently no 



