366 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
brown, lighter colored than the spots. The inner edges of the swimming lobes are beautifully and 
distinctly maculate, with alternating light and dark patches. The mantle is colored like the body, but 
the dark spots are wanting, and the dark reticulations are somewhat radiating. Length, 7 cm. 
Shell with a rather strong layer of lime, elliptical in outline; posterior sinus moderate. Length 
of shell, 30; breadth, 19 mm. 
Mayaguez, Porto Rico. 
Nine specimens in alcohol were obtained by the expedition, all probably young. The pattern 
of coloring is quite constant in all, though in some specimens there are but few of the dark, smoky, 
round spots. As the description is from alcoholic material only, it is impossible to tell what the colors 
may be in a living state. Most of the specimens are badly shrunken or drawn up by the alcohol. 
Tethys parvula (Guilding) Morch. Plate 53, fig. 14. 
Aplysia parvula (Guilding MS.) M6rch.Journ.de Conch., 1863, p. 22. 
Tethys parvula Pilsbry, Man., x vi, p. 83, pi. xxxvn, figs. 23-25, 1895. 
Body higher than wide; mouth placed well forward, with slightly wrinkled, thickened lips; 
rhinophores large, folded; tentacles rather small; eyes not seen; foot elongated, extending to a point 
behind, its border crimped; swimming lobes wide and almost auricled in front, narrower and united 
behind, closely inclosing the very large shell; mantle having a large oval opening which exhibits the 
shell. Excurrent siphon lateral, opening at posterior sinus of shell. Color, a dirty greenish white; 
border of foot, pleuropodia, and mantle opening intense black, as are the tips of the rhinophores. 
Length of animal, 20; diameter of mantle opening, 5; length of opening, 6 mm. 
Shell very large, solid, concave, covered with a rather thick epidermis, which peels on exposure 
to air; posterior sinus moderate, overhung by the epidermis; apex much incurved, callous, but having 
no recurved process. Interior calcareous, slightly iridescent, pinkish white, externally straw colored. 
Length, 13; breadth, 9; height, 5 mm. Length of sinus, 5 mm. 
Caballo Blanco Reef, Vieques, one specimen. 
This specimen is badly contracted by the alcohol, and is not in good condition to study. The 
species is remarkable for the great size and solidity of its shell, which is deeply concave and covers the 
whole animal. 
Subfamily DOLABRIFERIN2E. 
Genus DOLABRIFERA Gray, 1847. 
Animal ovate-oblong or sack-like, tapering toward the head. Eyes as in Tethys. Pleuropodia! 
lobes located behind the middle of the body, scarcely mobile, inclosing a large gill cavity. Mantle 
small; foot broad. Shell small, nonspiral, solid, and calcareous. 
Type, D. dolabrifera Cuvier. 
? Dolabrifera ascifera Rang. Plate 56, fig. 8. 
Aplysia ( Dolabella) ascifera Rang, Hist. Nat. Aplys., p. 51, pi. iv, figs. 7-9, 1828. 
Body (in alcoholic specimens) elongate ovate, swollen behind, more or less covered with warts; 
foot very large, of the same dimensions as the body and bordered by an expanded, wavy edge; 
rhinophores and tentacles small, shrunken; eyes minute, between the rhinophores and tentacles, 
a little nearer to the latter; dorsal slit in the posterior third of the body, to the right of the middle, 
about one-fourth the length of the body, buttonhole-like at its two ends. Right pleuropodial lobe 
overlapping the left, both lobes small. Length, 50 mm. 
Shell somewhat narrowed, the apex much callous with strong growth lines outside, dead white, 
within callous and shining, quite solid. Length, 14; breadth, 7 mm. 
Reefs, Guanica; Ponce, Puerto Rico; Ensenada Honda, Culebra; Caballo Blanco Reef, Vieques. 
All our numerous specimens, some of which are no doubt young, are contracted by the alcohol 
and are much shorter than the length given bv Pilsbry in the monograph of the Aplysiidce. The 
shells, however, are longer than the measurement given by him, but have the general form of those 
figured by him for D. ascifera, though they vary considerably, some of them in the direction of 
D. swiftii Pilsbry. They are all solid and milky white outside. 
? Dolabrifera sowerbyi Guilding. 
Dolabrifera sowerbyi Guilding, Conch, Icon., xvi, pi. I, fig. 2, 1868. 
Body in alcohol elongated, pear shaped, much swollen behind; foot, wide, having a narrow, sharp 
border at its junction with body; head small; rhinophores and tentacles short, shrunken and wrinkled; 
