116 MONODONTA. 



I have not seen this form. It is evidently closely allied to M. 

 sagittifera, but according to Dr. Fischer, may be separated by its 

 more elongated form, more acute spire, and close lines of color. 



M. TENER Troschel. PI. 35, figs. 17, 18. 



This species nearly allied to T. impervius and T. perdix, but is 

 apparently different ; I count 5 whorls, the upper eroded ; these are 

 moderately convex, the last compressed or even concave below the 

 suture, distinctly angular beneath, entirely smooth. The clear violet 

 ground is so densely marked with oblique, narrow, blackish, longitu- 

 dinal lines, that at a little distance the shell appears unicolored black. 

 The aperture is very oblique ; the greater part of the base is occupied 

 by a very large porcellanous callous, which is concave in the middle 

 and surrounded by a deep black zone. At the origin of the col- 

 umella is a little pit. The columella is very oblique, flat, and is 

 continued in a band parallel to the edge of the outer lip ; the nacre 

 is very beautiful, changing to violet. 

 Alt. 7, diam. 11 mill. (Philippi.) 



Habitat unknown. 



T. tener TROSCHEL in PHILIPPI, Conchyl. Cab., p. 141, t. 24, f. 2. 



M. TABULARIS Krauss. PL 35, figs. 14, 15. 



Shell small, conical, imperforate, rather solid ; the coloration 

 consists of rather broad longitudinal stripes of dark olive-green or 

 red, alternating with stripes of bright pink, bordered with lines of 

 delicate green, and frequently veined with the same tint ; the stripes 

 are continuous from suture to base, or are displaced or interrupted 

 at the periphery ; spire low-conic, apex eroded, orange-colored, the 

 following whorl, if eroded, showing iridescent blue-green nacre, 

 which is spirally grooved ; whorls about 5, smooth when not eroded, 

 the last obtusely subangulate at the periphery ; base rather flattened, 

 radiately striped with red and white, not eroded ; aperture oblique, 

 outer lip acute, edged with alternate green and white, smooth with- 

 in ; columella arcuate, thin, white, wide, covering the place of the 

 umbilicus with an ivory-white pad, which is closely appressed to the 

 body-whorl. Alt. 10, diam. 11 mill. 



Cape of Good Hope. 



Trochns tabnlaris KRAUSS, Die Siidaf. Moll., p. 97, t. 5, f. 30. 

 PHILIPPI, Conchyl, Cab., p. 142, t. 24, f. 4. 



The coloration of this species is peculiarly effective and delicate. 



