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PART I. 



DESCRIPTION OF SPECIES. 



CRUSTACEA. 



ENTOMOSTRACA. 



FAMILY CYZIC1DAE. 



CYZICUS, Audouin. 

 CYZICUS (EUESTHERIA) DRAPERI (Jones & Woodw.) 



1894. Esther ia Draper i and E. stotviana, Jones Woodward, 

 Geol. Mag., N.S. Dec. IV, vol. I, p. 289. PI. IX tigs, la c, 2. 



The original description runs as follows : - - "Size: Length of valve, 

 16 mm. Length of hinge-line, 11 mm. Height lO 1 /., mm. Valves 

 suboblong, straight above, slightly curved below, rounded at the 

 ends; anterior margin higher and less convex than the posterior. 

 The interspaces on the surface are ornamented with coarse shallow 

 pits, making an obscure reticulation. The urn bo is just in front of 

 the middle of the hinge-line." 



I have examined a number of specimens from the shale-band at 

 Siberia, Wodehouse, C. P. in the Cave Sandstone which belong to 

 this species. None of them attain the dimensions recorded by Jones 

 Woodward; the largest valve seen by me is 12 mm. long, 8 mm. 

 high and has a hinge-line of 8'/ 2 mm - The corresponding dimen- 

 sions on a number of the specimens are 7 1 /., mm., 5 mm. and 5 mm., 

 while some have a length of not more than 2'/2 nun - 



Several of the specimens show the details of the external markings. 

 The shape is somewhat variable, the smaller specimens approx- 

 imating more to that ligured by Jones & Woodward as E. stowiana. 

 All agree, however, in the possession of the concentric ridges and, 

 as far as can be seen, in the nature of the intercostal ornamentation. 



