FiSSURELLIDAE 107 



about perforation narrow, entire; anterior and posterior margins 

 crenulate. 



Genus DIODORA Gray, 1821 

 Diodora^82 meta^^^ (von Iheriug) PI. 21, fig. 134 



Alt., 4; length, 16; width at middle, 11.5 mm. Shell conical- 

 depressed, oblong-ovate, summit anterior to middle, aperture oval; 

 color white or grayish, rayed with darker shade, sometimes mossy 

 green; radiating riblets alternating in size, cancellated by strong, 

 regular, concentric ridges, nodular at intersections with ribs; interior 

 white, callus about perforation, dark-colored and slightly truncate 

 behind. 



Diodora cajenensis (Lamarck) PI. 21, fig. 136 



Alt., 12; length, 22; width at middle, 19 mm. Shell rather thick, 

 oblong-oval, conical; color white or buff with markings of light and 

 dark gray; summit anterior to middle; anterior slope straight or 

 slightly concave, posterior slope convex; orifice keyhole shaped, ex- 

 cavated; sculpture of three small ribs between two large radiating 

 ribs, crossed by concentric, lamellar ridges which become semi- 

 erect curved scales at intersections of ribs; interior white, polished, 

 translucent to exterior coloration; heavy callus about aperture which 

 is truncate behind with a depression immediately posterior; margins 

 finely and regularly crenulate; only anterior and posterior margins in 

 contact with flat surface. 



Diodora listerii^* (d'Orbigny) PI. 21, fig. 137 



Alt., 12; length, 38; width at middle, 25 mm. Shell corresponds 

 to D. cayenensis in general characters but is larger and heavier. 

 Sculpture of alternately larger and smaller ribs deeply cancellated 

 by strong, cordlike concentric ridges. Interior white; margins crenu- 

 late with the denticulations arranged in pairs. 



Genus RIMULA Defrance, 1827 

 Riniulaiss longa Pilsbry PI. 45, fig. 317 



Length, 6.5 mm., breadth, 3 mm., height, 1.8 mm., length of 



1*- Gr., dia., through; dora, hide, fur. 

 1*3 Lat., meta, cone, pyramid. 

 1^* Dedicated to Lord Martin Lister. 

 1®^ Lat., rima, a cleft, fissure. 



