OF SAISTTO DOMINGO. 



203 



MURICIDEA. Swains. 



M. c o r r u g a t a. Gabb, n. s. 



Shell short, broad, robust ; spire about equal in length to the mouth. Whorls, including the nucleus, seven ; 

 rounded and increasing- rapidly in diameter ; suture well marked ; eight large rounded longitudinal ribs, with broad 

 regularly concave interspaces. These are crossed by numerous revolving lines, sometimes alternating in size. 

 Aperture broad, canal short and recurved ; inner lip slightly encrusted and strongly ribbed transversely, especially 

 in advance ; outer rib also strongly ribbed internally. This character of the mouth will distinguish the species from 

 the following. Length .65 inch, width .4 inch. 



M. 1 a t a. Gabb, n. s. 



Shell short, broad, and robust ; spire and aperture about equal. Whorls seven (?) (the apex is corroded away)) 

 broad, angulated, obliquely truncated above. Body whorl very short and sloping with neai'ly straight lines to its 

 anterior end. Surface bearing nine broadly-rounded longitudinal ribs, crossed by numerous closely-placed and 

 rather large elevated revolving lines. Aperture broad and rounded behind, narrowing regularly in advance ; canal 

 short and nearly straight ; columella slightly encrusted, polished, and with no teeth or ribs on either inner or outer 

 lips. Length .45 inch, width .3 inch. 



From the preceding species tliis shell can be distinguished not only by the inside 

 of the month, as stated above, bnt also by its sub-angular form, sloping tops to the 

 whorls, and nearly straight converging anterior end, and by the closer-placed revolv- 

 ing sculpture and straighter canal. 



M. striata. Gabb, n. s. . ■ 



Thinner and proportionally longer than either of the two preceding. Spire elevated about equal to the aperture; 

 whorls eight, including the nucleus ; angulated. Body whorl sloping nearly straight above, convex below, the angle con- 

 stricted in advance. Surface ornamented by seven large ribs on the widest part of the whorls, which become obsolete 

 above and below. Crossing these below the angle are half a dozen linear ribs with broad smooth interspaces. These 

 latter ribs are well developed where they cross the others, but are much smaller in the concave spaces. Mouth 

 subovate, constricted in advance. Incrustation of the inner lip heavy, smooth, and with a projecting free edge ; 

 outer lip faintly striate internally. Canal twisted, with a broad imperforate umbilicus. 



Although about the same size as the two preceding sj)ecies, this shell can be at 

 once recognized by its thinner structure, its more slender shape, its more twisted 

 canal, and by the paucity of its spiral ornaments. 



TYPHIS. Montf. 



T. alatus. Sby. Quart. Jour., Vol. VI. p. 48, pi. 10, flg. 4. 



Very rare. Close to, but distinct from T. acuticosta, Con. of the Vicksburg 

 Eocene. 



T. o b e s u s. Gabb, n. s. 



Shell short, broad; spire very low ; whorls eight, sharply angulated ; concave above the suture, sloping convexly 

 below ; varices four to each whorl, acute-angular on their margins, and ending in a blunt process on the uj)per angle 

 of the whorl ; tubes moderate, pointed laterally, below each tube the surface of the shell is greatly swollen, and two 

 lines pass anteriorly, one being the margin of the old mouth, the other, in advance of the tube, being similar in 

 character and indicating another arrest in growth. Surface polished, marked by faint lines of growth, and crossed 

 below the angle by a few irregular transverse lines, not ribs. Aperture small, oval, bordered by a prominent, acute 

 raised margin ; canal closed, short, recurved ; front face of terniiual varix marked by five small ribs radiating from 

 the outer lip. Length 1. inch, width .75 inch. 



