MONODONTA. 109 



marked with a few spiral subimpressed lines w'hich are sometimes 

 obsolete, leaving the surface smooth ; color plumbeous aslien, often 

 with a pink tinge, speckled closely with white dots, and encircled 

 W'ith two dark bands which are articulated with larger spots of white ; 

 sutures impressed ; whorls 5, subconvex, the last forming the greater 

 portion of the shell, compressed, obtusely angulated, dej^ressed below 

 the suture, the surface of the base almost entirely occupied liy tlie 

 parieto-columellar area ; aperture very oblique, pearly, iridescent 

 inside ; outer lip acute, thin, continued on the base in an angle which 

 bounds the columellar area ; columella subhorizontal, thin, very wide,, 

 subconcave, white, bounded by a narrow brown streak outside. 



Alt. 9, diam. 10 mill. 



Neio Caledonian Archipelago, 



T. constellatus Souverbie, Jouni. cle Conch., 1863, p. 279, t. 12, f. 

 3.— Fisher, Coq. Viv., p. 271, t. 90, f 1. 



A very depressed, almost Trochita-shaped species. There is con- 

 siderable variation in the color-pattern. Unlike most of the preced- 

 ing species, the base is not lined with a white thickened continuation 

 of the columella. 



M. EXCAVATA Adams et Angas. PL 35, figs. 1, 2, 3, 



Shell small, imperforate, depressed-conic, oblique, light green, 

 closely maculated and mottled in minute pattern with dark olive, the 

 markings sometimes assuming the form of obliquely descending dark 

 bars; spire conoidal, the apex eroded, whitish; the penultimate 

 whoi-1 quite convex, ruddy or purplish ; suture well impressed ; 

 whorls 4, the last conic above, flattened beneath, carinate at the 

 periphery; almost the entire surface of the base occupied by the 

 large, very oblique aperture ; outer lip acute, arcuate, not thickened 

 witliin, inside brilliantly iridescent, smooth or nearly so; columella 

 subhorizontal, its edge arcuate, thin, acute, extending below ujwn 

 the base, forming a ledge within the basal lip ; parieto-columellar 

 area very large, eroded, concave, white. Alt. 5, diam. 6 mill. 



Xew Zealand. 

 Trochocochlea excavata Ad. and Ang., P. Z. S., 1864, p. 37. — 

 HuTTON, Manual N. Z. Moll., p. 97. 



A species allied to M. qonstellata, but smaller, lacking dark spiral 

 bands, more angular at the periphery, more concave beneath, and 

 with the columella prolonged in a distinct ledge within the basal lip. 

 To M. perplexa it is also related ; but is smaller, more angulated. 



