MOLLUSCA OF PORTO RICO. 
461 
Area adamsi (Shuttleworth) Smith. 
Area (Acar) adamsi (Shuttleworth) Smith, Journ. Liu. Soc., Zool., xx, p. 499, pi. xxx, figs. 6, 6u, 1888. 
Shell moderately solid, rhomboid, inflated, rounded in front, the hinge and base line parallel, 
the posterior end obliquely subtruncated; posterior ridge high but rounded ; beaks only moderately 
full, turned forward, separated by a narrow area; surface having numerous pseudo-ribs consisting of 
more or less connected blisters, with strong, concentric sculpture; teeth few, rather strong. 
Color whitish or brownish. There is a curved ridge below and inside of the muscular impressions. 
Length, 12; height, 7.5; diameter, 7.5 mm. 
Aguadilla; Ponce; Mayaguez; San Juan Harbor, Porto Rico; Vieques. 
Subgenus Scapharca (Gray, LS47) Dali. 
Area campechensis Ginelin. 
Area campechensis Gmelin, Syst. Nat., p. 3312, 1792. 
Area americana Reeve, Conch. Icon., ii, Area, fig. 21, 1844. 
Aguadilla; San Juan, Porto Rico (Gundlach). 
Area deshayesii Hanley. 
Area deshayesii Hanley, 111. Cat. Biv. Shells, p. 157, 1842. 
Area deshayesii Reeve, Conch. Icon., ii, pi. vn, fig. 47, 1844. 
Shell oblong, inflated, solid, subrhomboid, with high, full beaks which are separated by a rather 
narrow area, angled at the hinge line in front, with about twenty-seven strong, rounded ribs which 
are crossed by concentric threads; hinge teeth rather numerous, well developed. Color whitish, 
covered with a silky, brown epidermis. 
Length, 65; height, 45; diameter, 45 mm. 
Mayaguez; San Juan, Porto Rico; Vieques. 
Area secticostata Reeve. 
Area secticostata Reeve, Conch. Icon., Area, fig. 38, 1844. 
Shell irregularly rhomboid, somewhat elongated, with high, rather full beaks, situated at one- 
fourth of the distance from the anterior to the posterior end, solid, inflated, with a moderately wide 
area; posterior ridge not elevated, somewhat rounded; anterior end angular at the hinge; posterior end 
obliquely truncate below the hinge; surface sculptured with about thirty-five ribs, those of the middle 
and anterior end grooved; posterior ribs rounded; all except those on the posterior slope are more or 
less beaded; hinge long; the teeth numerous and well defined, but not high; the border within the 
shell is strongly denticulate. Color white; epidermis brownish, shaggy. 
Length, 85; height, 52; diameter, 52 mm. 
Mayaguez, Porto Rico, several young and worn valves. 
Area chemnitzi Philippi. 
Area chemnitzi Philippi, Zeitsehr. fiir Mai., VIII, p. 50, 1851. 
Area d’orbignyi Kobelt, Mart. Chemn. Conch. Cab., 2te Ausg., p. 57, No. 41, pi. xvi, figs. 7, 8, 1891. 
Shell irregularly triangular, slightly inequivalve, solid, with very high incurved beaks, with a 
lozenge-shaped area; anterior end angular at the hinge, but the angle projects but little beyond the 
general outline; posterior ridge high, somewhat rounded; surface sculptured with about twenty-five 
nodulous ribs, which are often flattened; epidermis softly spinose in the grooves of the anterior half 
of the shell, thick and lamellar on the posterior part; hinge short, teeth distinct; beak cavities deep; 
inner edge of the shell strongly dentate. Color white. 
Length, 30; height, 30; diameter, 30 mm. 
Playa de Ponce; Mayaguez Harbor; off San Juan; Catano; Boqueron Bay, Porto Rico; Culebra 
Island; Vieques. 
Some of these specimens are much larger than any of this species which have hitherto been 
reported. 
