RHYTIDA. 117 



M. CORYMBUS, Crosse. PL 27, figs. 22, 23. 



Scarcely perforated, rather thin, closety lamelliformly impressly 

 striate ; corneous, obscurely reticulated with chestnut-red, at the 

 suture maculated alternately with dark chestnut and j^ellowish ; 



aperture without plica. Diam. 5*5, alt. 3 mill. 



N. Caledonia. 



Subo;enus PLATYSTOMA, Ancey, 1882. 



*^ / / 



M. SATSSETI, Montrouzier PI. 25, figs. 4, 5. 



Almost imperforate, somewhat thin, rather distantly costu- 

 lately striate, with intermediate smaller striae ; yellowish white, 

 with chestnut undulating strigations ; suture rather deeply im- 

 pressed, la|t whorl obtusel}' subcarinate, blackish around the 



umbilicus. Diam. 15, alt. 8 mill. 



N. Caledonia. 



M. ASTUR, Souverbie. PL 25, figs. 8, 9. Magn. f . 



Scarcely perforate, thin, closely arcuately plicately striate, 

 greenish corneous, under an olivaceous brown epidermis, w r hich is 

 radiately undnlately strigate with chestnut; whorls 4, the last 

 subdepressed, obtusely subcarinate. Diam. 7, alt. 3 mill. 



N. Caledonia. 

 M. CHELONITIS, Crosse. PL 27, figs. 24, 25. 



Scarcely perforate, rather smooth, thin, pellucid; light yel- 

 lowish, maculated and reticulated with chestnut, some of the 

 maculations stronger above. Diam. 7*5, alt. 4 mill. 



N. Caledonia. 

 Genus RHYTIDA, Albers, 1860. 



* Aperture lamellate. 



R. BERAUDI, Gassies. PL 23, figs. 35-37. 



Subcarinate, widely, perspectively umbilicated, orange-brown 

 above, reddish brown below, with reddish incremental striae ; 

 whorls rugosely striate, decussated, especially below by revolving 

 impressed lines ; aperture bidentate, lip simple. 



Diam. 18, alt. 10 mill. 



N. Caledonia. 

 R. SUBSIDIALIS, Crosse. PL 23, figs. 38, 39. 



Widely, perspectively umbilicated, spirally sulcate, the sulcse 



