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its pair inserting in radular ribbon intemally io radular sac (fig. 206); 3) some smali connection of anterior extremity of radular sac with inner-vcn-tral surface of horizontal muscle (fig. 205: ih). Radula (fig. 88): rachidian toolh with 9 cusps, being central cups vcry broad and arched, and lateral cusps smali and uniformly sized; lateral tooth very broad and flattened, with 6 cusps, being fourth cusp larger and broad; inner marginal tooth spoon-like, broad terminal margin with 7 cusps; outer marginal tooth spoon-like, with terminal margin “V” shaped, with about 18 cusps of smali, uniform sizc. Salivary glands as described by Houbrick (1987: 27, fig. I9b), having glandular tissue also anterior to nerve ring (fig. 197). Anterior esophagus with two folds in ventrai region and two pouches in dorsał region with successive oblique septa (fig. 196). Middlc esophagus with dorsal pouches. Pos-terior esophagus single, without inner folds. Stornach (fig. 198) very large; inner surface almost entire smooth; central pad smali septum-like, in middle-ventral region, not covering duet to digestwe gland. No differentiable folds or sorting areas. Digestwe gland begins ventrally in stornach near style sac and runs two whorls posterior to it (fig. 194). Style sac simple, cylindrical, with a left smali fold, intestine origin in left region of style sac tip. Intestine naiTOw, contours dorsally style sac, in its right ventral region, runs anteriorly; in pallial cavity suddenly expands. Rectum very large, with fecal pellets compacted obliquely as in preceding species (fig. 193). Anus siphoned posterior situated from mantle border. Other details of digestwe system in Houbrick (1987a: 27).

Genital system. Małe: pallial spermoduet simple, almost all opened, thick glandular walled (fig. 193). Female: gonopericardial duet visible; pallial oviduct with bursa opening anterior to aperture of seminal receptacle; bursa contours left region of receptacle and stays posterior to it (fig. 199), other details see Houbrick (1987a: 29, fig. 19a). Brood pouch aperture a smali porę situated in middle region between right tentacle and right insertion of mantle (fig. 190), preceded by a posterior funow. Brood pouch two large chambers in dorsal region of foot, one in each side (fig. 191); each chamber U-shaped, with outer branch connected with brood pouch aperture (described above and by Houbrick 1987a: 29-33, fig. 2 lb). Within brood pouch about a thousand smali embryos, apparently in same development level (less than one whorl).

Measurements (MZSP 28255, in mm). 15.9 by 11.1; 13.1 by 8.5; 13.7 by 9.3.

Distribution. GulfofMexico and Caribbean Sea.

Habitat. Under rocks, medium to supra tidal, near estuaries.

Materiał examined. Venezuela; Nova Esparta; Margarita Island (Simone col.); Pedro Gonzales, Puerto Cruz, MZSP 28256, 31 specimcns; La lsleta, El Yaąue beach, MZSP 28344, 12 specimens (7/ii/1995); Porlamar, Caracola beach, MZSP 28255, 46 specimens.

Remarks. Houbrick (1987a: 27) dcscribes the color of head-foot as black but the specimens here studied are gray. The characters of female pallial gonoducts of the specimens examined are similar to description of Houbrick (1987a:29) but the distribution of bursa and seminal receptacle are little different if compared with that shown in fig. 19a of that paper, which shows the bursa almost entirely anterior to receptacle. In the specimens examined, the bursa contours the receptacle and stays posterior to it. It is important to establish, however, that specimens from Florida, studied by Houbrick, was not examined herein, and these differences show that further investigations are necessary.

Family Pleuroceridae

Genus Doryssa H. & A. Adams, 1854 (Type species: Bulimus atrus Bruguiere, 1792)

Doryssa ipupiara new species

(Figs 12, 57, 58, 75, 76, 89, 90, 207-224)

Types: Holotype MZSP 28687. Paratypes: MZSP 28688, 1 specimen; MZSP 28689, 1 specimen; MZSP 28690,1 specimen; MZSP 28265, 14 specimens; USNM 890884, 2 specimens. All from type locality.

Type locality: Brazil; Roraima; Apui lakę, Maraca Island (sta. INPA-mol 101, Motta, C.S. col.).

Diagnosis. Shell with shallow suture, acuminate, sculptured by strong spiral cords and axial threads. Eyes not visible extemally. Ctenidial vein very broad in its posterior half. Gili filaments long and