NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 119 



Page 



type. 18, Exfoliated pygidium, x2 (coll. cnd/1) ; U.S.N.M. 144706, 

 plesiotype. 



Figs. 19-24. M enomonia tuber culata Rasetti, n. sp 62 



19-21, Dorsal, lateral, and frontal views of cranidium, x5 (coll. cnc/2) ; 

 U.S.N.M. 144696, holotype. 22, Free cheek, x5 (coll. cnc/2) ; U.S.- 

 N.M. 144697, paratype. 23, 24, Lateral and dorsal views of cranidium 

 with somewhat shorter preglabellar field, x5 (coll. cnc/5) ; U.S.N.M. 

 144698, paratype. 



Figs. 25-27. M enomonia, sp. undet 63 



25, 26, Dorsal and lateral views of cranidium, x5 (coll. cnc/4) ; U.S.- 

 N.M. 144699. 27, Free cheek, x5 (coll. cnc/6) ; U.S.N.M. 144700. 



Plate 3 



Figs. 1-6. Norwoodella saffordi (Walcott) 65 



1, Artificial cast of counterpart of holotype, x3 (U.S.N.M. coll. 103) ; 

 U.S.N.M. 61595. 2, 3, Exfoliated cranidia, x5 (coll. cnd/1); U.S.- 

 N.M. 144612, plesiotypes. 4, Cranidium, X5. 5, 6, Pygidia, X7.5 (coll. 

 cne/2) ; U.S.N.M. 144613, plesiotypes. 



Figs. 7-9. Loxoparia obliqua Rasetti, n. gen., n. sp 112 



Dorsal, frontal, and lateral views of cranidium, x5 (coll. cnd/1) ; 

 U.S.N.M. 144727, holotype. 



Figs. 10, 11. Holcacephalus praecursor Rasetti, n. sp 68 



10, Partly exfoliated cranidium, x7.5 (coll. cnc/1) ; U.S.N.M. 144621, 

 holotype. 11, Exfoliated pygidium, xlO (coll. cnc/1); U.S.N.M. 

 144622, paratype. 



Figs. 12-14. Holcacephalus granulatus Resser 68 



12, 13, Exfoliated cranidia, X 10. 14, Exfoliated pygidium, xlO (coll. 

 cnd/1) ; U.S.N.M. 144620, plesiotypes. 



Figs. 15-21. Ankoura triangularis Resser 61 



15, 16, Dorsal and lateral views of exfoliated pygidium, x7.5. 17, Ex- 

 foliated pygidium, x7.5 (coll. U.S.N.M. 27d) ; U.S.N.M. 144702, 

 plesiotypes. 18, 19, Lateral and dorsal views of exfoliated cranidium, 

 X7.5 (coll. U.S.N.M. 27d) ; U.S.N.M. 144608, plesiotype. 20, Incom- 

 plete cranidium preserving test, x7.5. 21, Pygidium, x7.5 (coll. cnb/ 

 10) ; U.S.N.M. 144609, plesiotypes. 



Figs. 22-25. Hawkinsia minuta Rasetti, n. gen. n. sp 105 



22, Cranidium, X 10 (coll. cnc/1); U.S.N.M. 144713, paratype. 23-25, 

 Frontal, lateral, and dorsal views of cranidium, xlO (coll. cnc/1); 

 U.S.N.M. 144712, holotype. 



Plate 4 



Figs. 1-7. Norwoodella rotundicollis Rasetti, n. sp 65 



1, 2, Dorsal and lateral views of exfoliated cranidium, x3 (coll. cnd/1) ; 

 U.S.N.M. 144614, holotype. 3, Exfoliated cranidia, x3. 4, Free check, 

 X5. 5, Cranidium, x5. 6, Exfoliated pygidium, XlO. 7, Exfoliated py- 

 gidium, x8 (coll. cnd/1) ; U.S.N.M. 144615, paratypes. 



Figs. 8-15. Norzvoodella halli Resser 67 



8-10, Frontal, lateral, and dorsal views of cranidium, X7.5. 11, 12, Free 

 cheeks, x5. 13-15, Pygidia, x7.5 (coll. cnd/10) ; U.S.N.M. 144619, 

 plesiotypes. 



