the Caribcean Islands. 533 



Plekocheilus undulatus. / v>^ 



Pi. corpore olivaceo-nigro, pede subtus pallido; tentaculis 

 apice albentibus, oculis atris. 



Testa valida, turgida, longitudinaliter plicata, transversim in- 

 distincte striatula, ferrugineo-castanea, fasciis brunneis obliquis 

 undulatis ; anfractibus quinque. 



Carychium undulatum. Leach^ ZpoL Misc. 1. p. 83. t. 37. 

 Auricula Caprella. Lam,^ Anim, sans vert. vi. pars 2. p. 140. 



Habitat in montibus sylvosis Sti. Vincentii, passim ; truncis 

 ramisque obvius. 



Ova ovali-elliptica, indistincte corrosa : numerosa, magna, glu- 

 tine acervatim deposita et filo gelatinoso adjuncta: primum fla- 

 vescentia, nitida, mox (exsiccata) margaritaceo-calcarea, 



Pulli pallidi, testa diaphana, pulcherrime corrosa, sericeo ni- 

 tente, striis nullis, labiis simplicibus. Testa juvenis subdiaphana, 

 fasciis distinctioribus, senilis epidermide crassa rugosa fusco-' 

 glauca, fasciis evanidis, saepe profunde corrosa. 



This noble species occurs in immense numbers in the forests 

 of St. Vincent, generally withdrawn, but sometimes even copu- 

 lating in the day time. The ova are agglutinated to the vagi- 

 nating leaves of the Tillandsice^ which, from holding water, secure 

 a damp atmosphere at all times. The lately excluded shell long 

 stood in my cabinet as a nondescript Succinea ? with a depressed 

 spire. I have at last traced it ab ovo^ and from the examination 

 of this and the young shell of Bulimulus undulatus^ a beautiful 

 species which I shall hereafter describe, the learned Zoologist 

 will perceive the necessity of separating with caution such small 

 shells as do not bear on the labrum some positive mark of ma- 

 turity. In the young of Plekocheilus the whole shell is without 

 striae, and is beautifully corroded on its surface, the plicae being 

 smooth and distinctly marked as they are added by the first 

 operations of the pallium. In the young of the other snail we 

 observe numerous fine longitudinal and transverse striae, which 

 it will be in vain to look for in the parts added by the animal as 

 it advances in strength: a circumstance that would have led to 

 the multiplication of species, had not specimens been discovered 

 in various stages. 



