138 



ON PERMIAN ENTOMOSTRACA FROM 



ment which I had proposed for these forms, as ahove indicated, 

 and shoAvn him all my materials, he recommends me to annul 

 some of my determinations, and to group into the following species 

 (as far as the Bairdice are concerned) the forms which I had 

 sorted out as characteristic. 



Names now Proposed. 



Reference to 

 PJatesix. &x. 



Names given in the Ann. 

 Nat. Hist. 



1. Bairdia plebeia, Reuss... 



2. B. plebeia, var. caudata, 



{ 



3. B. plebeia, var. amygdalin a 



4. B. plebeia, var. elongata ... 



5. B. plebeia, var. Neptuni ... 



6. B. plebeia, var. Reussiana. 



7. B. plebeia, var. ventricosa.. 



8. B. Schaurothiana, Kirkby. 



9. B. Kingii, Reuss 



10. B. Kingii, var. compressa.. 



11. B. Berniciensis, Kirkby ... 



12. B. rhomboidea, Kirkbv 



PI. ix. figs 1 & 2 



„ fig. 10..., 



„ fig. 9 



„ fig. 12..., 



„ fig. 11..., 



„ fig- 4 



„ fig- 5 



„ fig- 6 



„ fig- 3 



„ fig- 14.... 



„ fig- 8 



„ fig. 7 



„ fig. 15.... 



PL x.fig-. 3 



Bairdia plebeia, Reuss. 

 B. mucronata, Reuss. 

 B. mucrouata, Reuss. 

 B. n. sp. ? 



B. mucronata? Reuss. 



B. plebeia,Reuss.var elongatti 



7 B. plebeia, Reuss. var Neptun i 



8 B. Reussiana, Kirkby. 



9 B. ventricosa, Kirkby. 



10 B. Schaurothiana, Kirkby. 



11 B. Kingii, Reuss. 



12 iB. plebeia, var. compressa. 



13 B. Berniciensis, Kirkby. 



14 B. rhomboidea, Kirkby. 



From his opportunities of studying the carapace-valves of both 

 recent and fossil Bairdice, Mr. Jones appears to have reason for 

 differing from me in the estimate made of the value of some fea- 

 tures upon which I had much depended, namely, the relative 

 gibbosity of the valves (shown in the lateral contour), and the 

 amount of ventral overlap. More particularly, my friend's views 

 are at variance with those advanced by me as to the sub-generic 

 relations of what I termed Bairdia reniformis, B. Jo?iesiana, and 

 B. truncata. These he believes to belong to Cytherideis, a sub- 

 genus established by him in 1856, for the reception of several 

 Cytheres nearly approaching Bairdia in many respects. 



For the sake of easier comparison, and to illustrate the gradual 

 development of varietal differences, it has been deemed advisable 

 to introduce a scries of carefully executed woodcut outlines of 

 the Bairdice above referred to. 



