THE NAUTILUS. 101 



A NEW SPECIES AND SUB-SPECIES OF JAMAICAN PLEURODONTE. 



HY HENRY VENDRYES. 



Pleurodonte (Pleurodonte) vacillans, n. sp. PI. YI, figs. 

 1, 2, 3. 



Shell rather solid, very slightly dilated transversely, depressed 

 turbinate above, depressed convex below ; color brown all over, 

 deepening slightly in tint and simulating an indistinct band running 

 along the centre surface of the spire whorls (except the apical) with 

 a dark brown band below the periphery of the last whorl encircling 

 the base of the shell and fading off to very light about and around 

 the umbilical region ; whorls a little more than five, apical obtuse, 

 the rest subplanulate except the last which is impressed above the 

 periphery and somewhat inflated above the impression ; the peri- 

 phery subacute and descending slightly near its extremity ; suture 

 linear, impressed. Sculpture on part of the antepenult whorl appar- 

 ently the same as in P. carmelita, in the rest for the main part, of 

 irregularly raised, drawn out growth lines, coarse in some places and 

 very fine in others ; aperture peroblique, sublunate, livid shining 

 within in fresh specimens; peristome not so stout as in P. carmelita; 

 the extremities joined by a callus spreading across the parietal wall, 

 upper margin simple, somewhat sinuously depressed above near its 

 commencement, basal margin reflexed, widening, and adnate for some 

 distance to the base of the last whorl which is inflated, but less so 

 than in subacuta. There are two small distant teeth within, like 

 those of P. subacuta, but of a brown color, as is also the peristome. 

 The umbilicus is covered in some specimens but not completely so 

 in others ; in the first case the basi-columellar part of the peristome 

 which forms the covering shows a shallow depression over the per- 

 foration beneath. Alt. 23, diam. 48 mm. 



Habitat : Silver Hill in the Parish of St. George, situated at an 

 elevation of about 4000 feet on the northeastern slope of the chain 

 of mountains in St. Andrew ; St. Catherine Park, in the neighbor- 

 hood of the habitat of C. carmelita, and in exactly similar stations to 

 those which the latter frequents. 



This shell so much resembles P. carmelita in some respects, and 

 P. subacuta in others, that one may be led at first sight to confound 

 it with one or the other of those species to which the particular 

 specimen under examination may show a preponderance of resem- 



