216 



ON THE TOPOGEAPIIY AND GEOLOGY 



C. bideutata. D'Orb., sp. 



Bulla bidentata, d'Orb., La Sagra, pi. 4, fig. 13-10. . , -v, 



Utricidus bidcntata, Cliemn. Man. Conch., Vol. I., p. 388. 



TOMATINA. A. Ad. 

 T. recta. D'Orb., sp. ' ' 



Bulla recta, d'Orb., La Sagra, pi. 4, bis., fig. 17-20. 



VOLVULA. A. Ad. -. 



V. cylindrica. Gabb, n. s. 



Shell minute, sub-cylindrical, anterior end rounded, posterior produced, acuminate ; surface with a few fine revolv- 

 ing strise in advance ; aperture narrow, linear, widening in advance ; anterior end of inner lip thickened, reflexed. 



Allied to V. (Bulla) acuta, d'Orb., La Sagra's, Cuba, pi. 4, fig. 17-20, but more 

 slender and cylindrical. That species narrows sensibly in advance. ' 



BULLA. Linn. ■ 

 B. granosa. Sby., Quart. .Jour., Vol. VL, p. 51, pi. 10, fig. 10. 

 B. paupercula. Sby., Quart. .Tour., A^ol. VI., p. 53. 



A shorter, broader and thinner shell than B. amygdala, (striata), to which it is 

 most nearly allied. 



In addition to the above I have about a dozen species of undetermined Gasteropods, 

 mostly minute. 



ACEPHALA. 



MARTESLi. Leach. . , . - • _ 



M. Si), indet. ■ . • 



A single imperfect little shell, showing no trace of the accessory valve. 



- TEREDO. Linn. . . ■ 



? T. Sj}. indet. 



A mass of tubes which may belong to a Teredo or to one of the allied genera. 



KUPHUS. Guett. ^ . - ' 



Furcclla, SejUaria. Lam. ■ ' " " 



K. iucrassatus. Gabb, n. s. 



Tube large, cylindrical, irregular, surface covered by lines of growth, substance thick ; apex often twisted or 

 other svise distorted ; divided by a longitudinal septum into two tubes, often of unequal size. 



Fragments of this species are very common in the brown earthy shale east of 

 Guayubin. The largest I have seen is a little over an inch in diameter, and they 

 usually occur in pieces of two or three inches in length. -I have never seen it-from 

 other localities. The shelly walls are often so thickened that the internal diameter is 

 not over half that of the outside. 



HOCELLAHIA. Bellev. . ' . . • . - 



R. Sp. ? ■ • ■ 



A pair of minute- valves, nearest to JR. cuneiformis in shape, found boring a large 

 shell. They are too small for satisfactory specific detei-mination. 



