MOLLUSCA OF PORTO RICO. 
481 
Tectarius muricatus Linnseus. 
Turbo muricatus Linnaeus, Syst. Nat., ed. x, p. 761, 1758. 
Littorina muricata Reeve, Conch. Icon., x, pi. n, fig. 11, 1857. 
Shell perforate, with about eight somewhat rounded whorls, which are slightly shouldered above, 
the sculpture consisting of about four revolving rows of somewhat sharp nodules, with from five to 
eight rows of flatter nodules on the base, which fade out into mere ribs at the umbilicus; aperture 
ovate; outer lip thickened, scarcely produced at the base; the umbilicus continuing down the 
columella as a groove. Color ashy, the interior of the aperture brown. 
Length, 20; diameter, 15 mm. 
Cabo Rojo light; San Geronimo; San Juan; Arroyo; Puerto Real; Aguadilla, Porto Rico; Cabal lo 
Blanco, Vieques; Ensenada Honda, Culebra; West Indian region; Florida Keys. 
Tectarius trochiformis Dillwyn. 
Turbo trochiformis Dillwyn, Cat. Rec. Sh., ii, p. 826, 1817. 
Tectarius nodulosus Tryon (part), Man., ix, p. 258, pi. xlviii, fig. 72, 1887. 
Shell imperforate solid, with about eight whorls, which are sculptured with revolving rows of 
strong, sharp nodules. There are two rather pronounced rows of nodules on the upper whorls, one 
just below the suture, another lower down forming a shoulder. On the last whorl there are three of 
these more conspicuous rows, the two lower ones forming a biangulation on the periphery. Besides 
these there are revolving threads and rows of small nodules covering the entire shell; aperture suboval, 
outer lip rather thin; columella wide, excavated, base produced; operculum paucispiral. The shell is 
generally dark lead-color, the nodules lighter; aperture dark brown with a white stripe below. 
Length 18; diameter, 13 mm. 
San Geronimo; Aguadilla; Puerto Real, Porto Rico. 
This mollusk is quite common on the lower Keys of Florida, and is often confounded with 
Echinella nodulosa Pfeiffer, which it somewhat resembles. The former lias a paucispiral operculum, 
while that of the latter is multispiral. 
Family LITIOPID^E. 
Genus ALABA A. Adams, 1862. 
Shell elongated, pointed, with numerous rounded whorls which may be smooth or spirally lineate, 
with irregularly distributed varices; aperture oval; lip scarcely thickened, smooth within; columella 
subtruncate at the base. 
Alaba tervaricosa C. B. Adams. Tlate 58, tig. 8. 
Alaba tervaricosa Morch, Malak. Blatt. xxiir, p. 57, 1876. 
Rissoa tervaricosa C. B. Adams, Proc. Best. Soc. Nat. Hist., n, p. 6, 1845. 
Shell with about thirteen rounded whorls which gradually increase, the first five or six dark 
colored and smooth, the remainder whitish or ashy, often marked with brownish, and sculptured with 
very delicate revolving threads, which are reticulated by the growth lines; there are a number of 
rounded varices on the whorls; aperture oval; columella slightly truncate below. 
Length, 6; diameter, 2.5 mm. 
San Juan Harbor, Porto Rico; one shell; widely distributed. 
A. rrielnnura Adams appears to be only a more slender variety of the same species. 
Family SOLARIIDtE. 
Genus SOLARIUM Lamarck, 1799. 
Shell widely umbilicated, conic, depressed, angular at the periphery, solid; nucleus sinistra!, 
oblique, whorls sculptured; aperture subquadrangular; umbilicus funicular bordered by a crenelated 
carina; columella vertical; operculum horny, spiral, concave, or flat externally, with a tubercle on its 
internal face. 
Solarium nobile Hanley. 
Solarium nobile Hanley, Thes. Conch., nr, p. 230, fig. 35, 1866. 
Umbilicus rather narrow, deep, the crenulations surrounding it very strong; the suture well 
marked; there are four strong rows of elongated tubercles on the whorls, and on the upper whorls 
here are two fainter rows in the sutures; periphery narrow, rounded; base with five or six revolving 
