MOLLUSCA OF PORTO RICO. 
381 
Pleurodonte bornii Pfeiffer. Plate 54, figs. 2, 3. 
Helix bornii Pfeiffer, Conch. Cab., neue Ausg., pi. 8, figs. 5, 6, 1846; Mon. Hel. Vir., I, p. 391, 1848. 
Possibly only a variety of P. marginella Graelin, which is distributed through eastern Cuba. 
There are two forms in Haiti which may be only varieties of P. marginella. P. bornii has delicate 
revolving striae which cut the upper surface of the shell into very fine granules. The umbilicus is 
wide; and there is a single, revolving, dark brown band above and below on a light ground. 
Height, 15; diameter, 37 mm. 
Caguas; San Juan, Porto Rico. 
Subgenus Polydontes Montfort, 1810. 
Section PARTHENA Albers, 1850, 
Pleurodonte angulata Ferussac. Plate 54, fig. 1. 
Helix angulata Ferussac, Prodr., No. 134, 1821; Hist. Nat. Moll. Terr., pi. 61, fig. 2. 
Shell imperforate, lenticular, thin, slightly rounded above, more inflated below, especially in 
umbilical region; whorls four, rapidly increasing, flat, with strong growth lines, slightly granulous 
above and below; suture not at all impressed; periphery sharply keeled; aperture but slightly oblique, 
its lip reflected above and below; columella curved, deeply inserted; parietal callus thin. The general 
color of the shell is milky white, and when fresh it is covered with a very thin horn-colored epidermis. 
There are sometimes faint traces of revolving lines of color on the under surface. 
Height, 20; greater diameter, 45; lesser, 34 mm. 
El Yunque, Porto Rico. 
Pleurodonte obliterata Ferussac. 
Helix obliterata Ferussac, Prodr., p. 136, 1821; Hist. Nat. Moll. Terr., pi. 61, fig. 3. 
Pleurodonte obliterata Pilsbry, Manual, v, p. 69, pi. vi, figs. 51, 52, 1889. 
Closely allied to P. angulata , but is heavier, less inflated below, and does not have so sharp a 
keel. There are some half dozen revolving color bands on the base of the shell. This tine species 
is not given in Crosse’s list, but is found in Porto Rico according to Pilsbry. 
Section LTJQ,TJILLIA Crosse, 1892. 
Pleurodonte luquillensis Shuttleworth. Plate 2, fig. 16. 
Helix luquillensis Shuttleworth, Diagn. neue Moll. Berner Mitth., 1854, p. 40. 
Shell imperforate, conoidal, elevated, solid, dark, with rather feeble growth lines and covered 
with a very fine, microscopic reticulation; whorls five and one-half, the earliest scarcely convex, the 
later ones more rounded; last whorl rounded, flattened on the periphery, and having an almost 
obsolete carina; aperture oblique, rounded; peristome thick, slightly reflected, white; columella 
oblique, rather deeply entering, with a faint tooth at its base; parietal wall having a thin callus. 
Height, 34; greater diameter, 34; lesser, 30 mm. 
El Yunque, Porto Rico. 
This fine species is of a nearly uniform dark-chestnut color throughout, but sometimes shows 
faint, darker spiral bands within the aperture. 
Section THELIDOMTJS Swainson, 1840. 
Pleurodonte lima Ferussac. Plate 54, fig. 4. 
Helix ( Helicogena ) lima FCrussac, Prodr., p. 81, 1821; Hist. Nat. Moll. Terr., pi. 46, figs. 1, 2. 
A well known and abundant species, closely related to P. incerta and P. castrensis. The earlier 
whorls are light colored and but slightly granular, the last whorl is covered with tine, sharp, whitish 
lustules on an ashy brown ground, sometimes having darker streaks following the growth lines. 
Cayey; San Juan; Anasco; Aguadilla; San Geronimo; Catona; Caguas, Porto Rico. 
Pleurodonte castrensis Pfeiffer. Plate 54, fig. 5. 
Helix castrensis Pfeiffer, P. Z. S., 1856, p. 386. 
Shell imperforate, with somewhat elevated spire and swollen base, the upper shell, except the 
earlier whorls, covered with very fine, revolving sculpture, making the surface reticulated; the base 
having faint scattered pustules near the aperture; whorls nearly five, slightly convex, the last 
