1 SYNONYMY OF ACHATINELLUXE. 



loss of the forest there is less precipitation on the heated soil, 

 and what water falls is not conserved. Whether the earlier 

 destruction of low-lying forest was due to human agency is 

 not known, but in the absence of any other known cause 

 that seems likely. 



The change from humid to arid conditions in the lower 

 zone seems to have been too rapid to admit of the evolution 

 of many arid country species. There is one Succinea which 

 lives under volcanic rocks in the most arid places; a species 

 of Bifidaria is often found in dry country, and a few Lept- 

 achatinas exist in similar places. In general however, one 

 finds little or nothing to encourage search on the slopes of the 

 lower zone. 



The same tale of increasing aridity is heard from the tuff 

 cones of the Kona coast, where deposits of fossil forest-snails 

 occur on Koko Head, Diamond Head, Punchbowl, and others. 

 These desolate cones, furrowed with gullies, chill the traveller 

 approaching Honolulu with their austerity. Of herbage there 

 is now little, save for a thin line of dusty algarobas (Prosopis} 

 bordering the shore and straggling up the gulleys, and tufts 

 of dry grass which may harbor the dry country Succinea and 

 Bifidaria. In Pleistocene times, between periods of activity 

 and after the eruptions ceased, these cones were heavily 

 wooded, with a copious snail fauna. Amastra, Leptachatina, 

 Tornatellinidce, Lyropupa and Nesopupa, Endodonta and 

 Nesophila, Zonitidce, etc. found congenial environment, if we 

 may judge by the abundance of individuals. 



NOTES ON THE SYNONYMY OP ACHATINELLID^E. 



The specific synonymy of Achatinellida has been discussed 

 by Pfeiffer in the various volumes of the Monographia Heli- 

 ceorum, by Newcomb (1858), Dr. W. D. Hartman (1888), 

 D. D. Baldwin (1893) and Mr. E. E. Sykes (1900), all of 

 whom have given synonymic lists of the species known to 

 them. Messrs. Gulick and Thwing have also made sugges- 

 tions. While the synonymy of the present work differs 

 widely from previous arrangements, it has not been thought 

 desirable to occupy space with criticism of the views of other 



