Palceozoic Bivalved Entomostraca. 271 



but is fuller (more convex) on the sides, in this respect sur- 

 passing even var. a {J. c. fig. 7). It may therefore be taken 

 as var. d^ or ohescij if a subsidiary name be requisite. 



B. symmetrica was found also in the Frojel sliale of Goth- 

 land by Prof. G. Lindstrom (Ann. & Mag. Nat. Hist. ser. 6, 

 vol. i. p. 397). 



4. BijtJiocypris pliaseohiSj Jones, var. elongata^ nov. 

 (PI. XV. figs. 8 a, h, c.) 



Proportions :— L. 15. H. 7. Th. 8. 



This is longer and proportionally lower than the type, and 

 has a straighter back ; but its flat sides, rounded ends, in- 

 curved ventral margin, and edge view, similar to that in 

 figs. 115, 12 Z>, pi. vii. Ann. & Mag. Nat. Hist. ser. 5, 

 vol. xix., indicate its close alliance to B. jjhaseolus. We may 

 term it var. elongata. 



5. Bythocgpris concinna, Jones. (PI. XV. figs. 11a, b.) 



Proportions:— L. 15. H. 8. Th. 8. 



This appears to be referable to fig. 6, pl. v. Ann. & Mag. 

 Nat. Hist. ser. 5, vol. xix. pp. 186, 187. It is found also at 

 four other Swedish localities {op. cit. June 1888, p. 397). 



6. Bythocypris Phillipsiana, Jones &. Holl, var gotlandica^ 



nov. (PI. XV. figs. 9 a, h, c.) 



Proportions :— L. 14. H. 9. Th. 7. 



This is evidently another variety of the persistent * species 

 B. Phillijysiana, but is more compressed (that is somewhat 

 flatter on the sides) than either the type or any of the pub- 

 lished varieties. 



IV. Aparchites, Jones, 1889. 

 (PI. XV. figs. 12, 13, 14.) 



These specimens have such simply lenticular and round 

 carapaces that at first sight they look as if they belonged to 

 Polycojje, but they have too much hinge-line for that genus. 

 They are more nearly allied to Primitia lenticularis, J. & H. 

 (Ann. & Mag. Nat. Hist. May 1886, p. 408) ; but differ- 



* From Silurian to Carboniferous times. See Ann. & Mag. Nat. Hist. 

 March 1887, pp. 187, 188. 



