MOLLUSC A OF PORTO RICO, 
457 
Subgenns Fustiaria Stoliczka, 1868. 
Dentalium stenoschizum Pilsbry & Sharp. 
Dentaliun stenoschizum Pilsbry & Sharp, Man., xvn, p. 128, pi. xix, figs. 18-21, 1897. 
Shell considerably curved especially toward the smaller end, the earlier part slender, rapidly 
increasing in the maturer part; smooth and polished throughout, aperture somewhat oblique, 
compressed a trifle laterally, peristome thin; anal opening circular, having a very long, narrow slit on 
the convex side of the shell and nearly one-third of its length Color milk white, tinted a little with 
brownish on the earlier growth. 
Length, 35; greatest diameter, 3.4 mm. 
Mayaguez, Porto Rico, one fine, half-grown shell. 
Genus CADULUS Philippi, 1844. 
Shell small, tubular or oval in section, somewhat arcuate, more or less swollen at. or above the 
middle, contracting toward the aperture; surface smooth or delicately striate. 
Section POLYSCHIDES Pilsbry & Sharp, 1897. 
Cadulus carolinensis var. bushii Dali. 
Cadulus (carolinensis var. ?) bushii Dali, Blake Report, n, p. 430, 1889. 
Cadulus carolinensis var. bushii Pilsbry & Sharp, Man., xvn, p. 153, pi. xxxm, figs. 58, 59, 1897. 
Shell of medium size, semitransparent, glossy, bluish white, nearly circular throughout; greatest 
diameter about at the anterior third, abruptly constricted behind the swollen part, well curved; 
aperture oblique, subcircular, in flexed along the convex margin. 
Length, 6.5; diameter, 1.25 mm. 
Mayaguez, Porto Rico, a large number of specimens. 
Section GADILA Gray, 1847. 
Cadulus minusculus Dali. 
Cadulus minusculus Dali, Blake Report, II, p. 432, 1889. 
Cadulus minusculus Pilsbry & Sharp, Man., xvii, p. 164, pi. xxxii, figs. 42, 43, 1898. 
Shell minute, curved, moderately swollen near the middle, regularly curved on the convex side, 
but slightly curved on the concave side, both ends small; surface smooth, glossy whitish; aperture 
circular. 
Length, 2.3; diameter, a little more than 0.5 mm. 
Mayaguez, Porto Rico, one shell. 
Cadulus amiantus Dali. 
Cadulus amiantus Dali, Blake Report, II, p. 431, pi. xxvn, fig. 7, 1889. 
Shell rather elongated, moderately curved, the very gradual swelling about one-fourth of the 
way back from the anterior end; mouth not oblique, with the posterior opening circular. Color milky 
white, somewhat translucent. 
Length, 5.75; diameter, 1.5 mm. 
Mayaguez, Porto Rico, a large number of shells. 
Cadulus acus Dali. 
Cadulus acus Dali, Blake Report, n, p. 432, pi. xxvii, fig. 11, 1889. 
Shell small, slender, curved, milky white, variegated with translucent patches and markings on 
the anterior half which is smooth and shining; posterior half or third of the shell sculptured with 
very fine, annular grooves; greatest diameter immediately behind the aperture, from which there is a 
gradual diminution in size to the posterior end; the slope from the swelling to the anterior end is 
rapid. 
Length, 8; diameter of aperture, 0.5; greatest diameter, 0.75 mm. 
Mayaguez, Porto Rico, three specimens. 
Besides the above, a number of broken specimens of Cadulus were obtained at Mayaguez which 
are not in a condition to be identified. 
