the Palceozoic B waived Entomostraca. 



227 



projection of the marginal rim, and by being turned inwards 

 for a considerable depth. Its extreme edge has for most of its 

 length a delicate raised rim, which, however, passes outwards 

 and backwards to join the great marginal ridge, where the 

 latter projects as a thick, sharp-edged crest along the posterior 

 edge of the valve. Somewhat analogous features may be 

 traced in Primitia cristafa, J. & H., Ann. Nat. Hist. ser. 3. 

 vol. xvi. pi. 13. tig. 1. 



The dorsal border of Moorea silurica is indented along its 

 marginal ridge, so as to form with its fellow, if similarly con- 

 structed, a narrow elliptical depression at the back, along the 

 hinge-line, as in P. cristata above alluded to. 



Our specimens were found in a band of micaceous lime- 

 stone in the U23per Ludlow rocks, wnth Kirlcbya fibula^ at 

 Hales End, Malvern, Avhere it was not uncommon. 



Table of Measurements in thousandtlis of an inch. 



Name. 



Reference. 



Length. 



„ . , , Thick- 

 Height ^gsg_ 



Cythere corbuloides, sp.n 



Griudrodiana, sp.n 



Bairdia Phillipsiana, sji.n 



Thlipsura coi-pulenta, sp.yi 



tubei'osa, s^y. n 



V-scripta, sp.n 



Cytlierellina siliqua, var. grandis, nov. 



(oi'dinary variety) 



, var. tersa 



, var. ovata 



siliqua, Jones, sp. (ordinary var.) 



„ (another specimen) 



^chmina cuspidata, s/?. n ] 



clavxdus, sp.n 



Beyrichia intermedia, sp. n 



Primitia lentieularis, sp. n 



umbilicata, J. i^- H. 



bipuuctata, Salter 



excavata, sp. «.§ 



Kirkbya fibula, sp. m.§ 



.Moorea sihu-ica, sp.n.^ 



PI. XV. f. 4, p. 21ll 



vroodcut,f. l,p. 212' 



PLXlV.f. 7,p. 2131 



PI. XV. f. 1, p. 214| 



„ f. 2, p. 214 



„ f. 3, p. 214 



PI. XIV. f.l, p. 217 



„ f. 2, p. 21 7 



„ f. 3, p. 217 



„ f. 4, p. 217 



„ f.0,p.217 



„ f. o, p. 217; 



PI. XIV. f. 8, & ! 



woodcut,f.2,p.218 



„ f.3,p.2ia 



PI. XV. f. 7, p. 218 



woodcnt,f.4, p.219 



PI. XV. f. 0, p. 220, 



woodcut, f. 5, p. 220 



PI. XV. f. 10, p. 222| 



„ f.0,p.224 



„ f. 8, p. 226 



41 



24t 



53 



50 



43 



32 



83 



53 



33 



70 



53 



46 



68 



47 

 22 

 44 

 37 

 50 

 33 

 32 

 38 



11 



33t 



30 



23 



20 



42 



24 



17 



45 



24 



20 



33 



38 

 17 

 33 

 27 

 37 

 25 

 20 

 27 



35 

 10.? 

 26 

 33 

 19 

 16 

 39 

 26 

 16 

 40 

 p 



? 



? 



24 



? 



? 

 22 

 14 

 24 



* Large valve. 



t Another specimen, found lately, measures -rg^ inch in length, and 

 TT-g^ in height. 



X Smaller valve, -rl^ inch. 



§ The thickness in the last three species is obtained by doubling the 

 thickness of the single valve. 



