Palceozoic Bivalved Entomostraca. 409 



Present in the Smith Coll. no. 36, railway-cutting, side of 

 Severn, Ironbridge ; and in Vine Coll. LXVi&n, Shales over 

 the Wenlock Limestone. 



10. Primitia pauciinmctata^ Jones and Holl. 

 (PI. XIV. figs. 3 a, 3 I.) 



Primitia variolata, var. paiicijmnctata, J. & H. op. cit. p. 41'9, pi. xiii. 

 figs. 6 c, 6 d, 



p ,. r Fig. 3 : L. 14. H. 8. Th. 7. 



Proportions : | ^.^^^^^ -^ ^gg^ ^ ^ ^^ ^ g_ ^j^_ ^ 



We find that perfect specimens do not possess the supposed 

 antero-dorsal rim or marginal extension indicated in fig. 6 c, 

 above quoted. The absence of a rim and its more ovate out- 

 line, besides its ornament, distinguish it from P. variolata^ 

 and being constant in occurrence it may fairly claim a specific 

 standing. 



It occurs in the Vine Coll. xxiii,2, bed 25 (common) ; xxni, 

 bed 25* (not rare) ; and LXVlu & u, Tickvvood Beds. 



11. Primitia humilisy sp. no v. 

 (PL XIV. figs. 6 a, 6b, da, 9 b, 9 c.) 



p ,. r Fig. 6 : L. 10. H. 6. Th. 4. 



Proportions: [^'l q .^ j^^ ^^ H. 8. Th. 6. 



Valves nearly oblong, but rounded at the ends ; not very 

 convex, compressed forward, steep at the edges, but less so 

 anteriorly. Sulcus constricted dorsally, so as to form a rather 

 deep subcentral pit. Dorsal view cuneiform, rounded at the 

 thin end (anterior), and truncate behind. This is not a rare 

 form. Some few specimens show a very faint punctation. 

 Fig. 9 c shows an interior, with the dorsal edge and its liinge- 

 line. Figs. 6 a, b, evidently represent a young form of the 

 same lowly but characteristic species. In the Smith Coll. 

 no. 51, there are two very small individuals from Woolhope. 

 In the Vine Coll. XXV, bed no. 25 ; XXXVI4, bed no. 37 ; 

 LXiir, bed no. 25 ; LXIV4, s, 9, bed no. 37. 



12. Primitia valida, sp. no v. 

 (PL XIV. figs. 7 a, 7 b, 7 c.) 



Proportions:— L. 18. H. 12. Th. 10. 



A large, thick, Leperditioid Primitia, very convex along 

 the ventral region and at the posterior third ; compressed dor- 

 sally. Surface finely reticulated, often obscured by weather- 

 ing. Valves marked with a shallow, broad, subcentral pit. 

 Carapace half as long again as high, and almost as thick as 

 high. Edge view subovate, sharp in front ; end view sharp 



