■ 



THE BOTANK A I M. VGAZTNR 



[Vol. XXI. No. 24 



when viewed from the valve, with high mantle and sharp edge 

 between valve and mantle. Valve slightly concave in sagittal: 

 longitudinal plane, vaulted in transverse-longitudinal plane. 

 Foramen elliptic-lanceolate. Hoop almost equal to half the 

 length of mantle, not constricted. Horn arising within the 

 corners, with their short roots directed diagonally outward, and' 

 straight in their remaining part, provided with coarse spinules. 

 At the junction-point of both posterior horns of every cell, 

 except the lowest one in a chain, there is a minute tooth-like 

 process by which cells are united together. 



Loc. in Jap. : Cape Goza in Prow Shima (Aug., 2, 1904). 



Hitherto-known : Hongkong (Schroder). 



The present species very much resembles Ch. boreale Bail, in* 

 general aspect, the difference however being at once manifest in 

 the possession of teeth on posterior horns. It is distinguished 

 from Ch. denticulatum Lauder by the form and size of cell and 



C. ii ano denticulatum Sp. nov. 



: P< rtion of a chain with terminal cell :it t lie anterior extremity, viewed 

 slightly obliquely, '■;"; Fig. 6: Junction-point of the same, 2-f£; 

 I ig. c : Cell Been from the ralve, : '',"'. 



