PLATE X. 



FIGS. PAGE 



1. Holcostephanus cf. baini (Sharpe) ... ... ... ... ... 199 



Apertural view of the specimen shown in the previous plate, fig. 2. 



2. Holcosteplianus rogersi sp. nov. ... ... ... ... ... 201 



Another view of the specimen shown in the previous plate, fig. 3. 



3. Holcosteplianus modderensis sp. nov. ... ... ... ... 202 



'da. Apertural view. Modeler Drift, Sunday's Kiver. In the col- 

 lection of the Geological Society of London (No. 10976). 



4. Meyeria schwarzi sp. nov. ... ... ... ... ... ... 212 



4. Fifth and sixth abdominal segments and telson, viewed dor- 

 sally ; 4, telson x 2; 41>, lateral view of abdominal segments 

 ii.-vii., with a trace of the swimming appendage of segment 

 vi., x 2. The same specimen has already been shown in plate 

 viii., fig. -2-2. 



