MOLLUSCA OF PORTO RICO. 
453 
Ischnochiton striolatus var. funiculatus Carpenter. 
Ischnochiton funiculatus Carpenter MS. 
One specimen was taken at Puerto Real which is probably this. Mr. Pilsbry regards it as a 
variety of I. striolatus Gray. 
Ischnochiton papillosus C. P>. Adams. 
Chiton papillosus C. B. Adams, Proc. Bost. Soc. Nat. Hist., 1845, p. 9. 
Ischnochiton papillosus Pilsbry, Man., xiv, p. 114, pi. xxi, figs. 40, 41, 1892. 
Shell small, oval, carinated, the side slopes faintly convex; surface not divided into distinct 
areas, apparently smooth but really closely granulate throughout. Color whitish, mottled with olive 
green, or uniform greenish or brownish. 
Length, 8; breadth, 5 mm. 
Ensenada Honda, Culebra. 
Ischnochiton reticulatus Reeve. 
Chiton reticulatus Reeve, Conch. Icon., pi. xv, fig. 83, 1847. 
Eastern Porto Rico (Gundlach). 
Subfamily CHITONIN/E. 
Genus CHITON Linnaeus, 1758. 
Valves wholly external, the beak of the tail, valve median or anterior; insertion plates longer 
than the eaves, slit into deeply and finely pectinated teeth. Girdle covered with closely imbricating 
convex, smooth, or striated scales. 
Chiton tuberculatus Linnaeus. 
Chiton tuberculatus Linnseus, Syst. Nat., ed. x, p. 667, 1758. 
Chiton tuberculatus Pilsbry, Man., XIV, p. 153, pl.xxxm, figs. 58-60, 1892. 
Shell oval-oblong, rather elevated, carinated; the side slopes nearly straight ; lateral areas raised, 
sculptured with about five cord-like, radiating riblets, which are usually interrupted and broken and 
bear low tubercles; central areas smooth along the ridge, the sides sculptured with longitudinal riblets 
curving inward; end valves closely tuberculate. 
Color varying from light olive to dark green, sometimes unicolored, generally speckled on the 
side areas and end valves; some of the valves have a dark stripe on the ridge. 
Length, 60; breadth, 33 mm. 
Hucares; San Juan; Ponce Reefs; Aguadilla; Guanica, Porto Rico; Caballo Blanco, Vieques. 
Chiton, tuberculatus var. assimilis Reeve. 
Chiton assimilis Reeve, Conch. Icon., pi. xiv, fig. 76 (right-hand figure), 77 b, 1847. 
Fawn-colored, with white dots on the lateral areas; carina banded with brown; girdle light 
green; central areas sculptured with fine, close riblets. 
Guanica, Porto Rico. 
Chiton squamosus Linn tens. 
Chiton squamosus Linnseus, Mus. Ludov. Ulricse, p. 465, 1764. 
Chiton squamosus Pilsbry, Man., xiv, p. 155, pi. xxxv, figs. 80-82, 1892. 
Shell oblong, elevated or depressed, carinated, the side slopes somewhat convex; surface of lateral 
areas minutely beaded; central area smooth, lusterless. Color buff, the central areas regularly and 
conspicuously striped longitudinally with gray or black. 
Length, 60; breadth, 32 mm. 
Aguadilla; San Juan; Hucares, Porto Rico. 
Chiton viridis Spengler. 
Chiton viridis Spengler, Skriv. af Nat. Selsk., iv, p. 70, pi. vi, fig. v, 1797. 
Shell oval, somewhat elevated and carinated, side slopes slightly convex; lateral areas strongly 
raised, sculptured with three or four low, radiating ribs, bearing low, rounded pustules, sometimes 
without radiating ribs; central areas smooth in the middle but sculptured along the diagonal lines with 
