NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 125 



Page 



No. 2); U.S.N.M. 144556, holotype. 23, Cranidium, x7.5. 24, Free 

 cheek, x7.S (coll. Oder No. 2) ; U.S.N.M. 144557, paratypes. 



Plate 15 



Figs. 1-12. Dunderbergia tennesseensis Rasetti, n. sp 71 



1-3, Dorsal, lateral, and frontal views of cranidium, X2 (coll. cnw/14) ; 

 U.S.N.M. 144628, holotype. 4, Cranidium, x3. 5, Cranidium, xS. 6, 

 Free cheek, x2 (coll. cnw/14) ; U.S.N.M. 144629, paratypes. 7, 

 Hypostome tentatively attributed to the species, X 10. 8, Cranidium, 

 X5. 9, 10, Dorsal and posterior views of pygidium, x3. 11, Pygidium, 

 X5 (coll. cnw/20) ; U.S.N.M. 144630, paratypes. 12, Free cheek, x3 

 (coll. cnu/7) ; U.S.N.M. 144631, paratype. 



Figs. 13-18. Dunderbergia longijrons Rasetti, n. sp 7Z 



13-15, Dorsal, frontal, and lateral views of cranidium, X5 (coll. U.S.- 

 G.S. 2970) ; U.S.N.M. 144632, holotype. 16, Cranidium, X5. 17, Ex- 

 foliated cranidium, x4. 18, Pygidium, XlO (coll. U.S.G.S. 2970); 

 U.S.N.M. 144633, paratypes. 



Figs. 19-26. Coosella perplexa ( Palmer) 50 



19-21, Dorsal, lateral, and frontal views of cranidium, x3. 22, 23, Py- 

 gidia, X3 (coll. cno/14) ; U.S.N.M. 144577, plesiotypes. 24, Exfoliated 

 pygidium, Xl-5. 25, Free cheek, X3. 26, Exfoliated cranidium, x3 

 (coll. cno/15) ; U.S.N.M. 144578, plesiotypes. 



Plate 16 



Figs. 1-7. Aphelaspis buttsi (Kobayashi) 87 



1, 6, 7, Cranidia, x4. 2, 4, Pygidia, X2. 3, Pygidium, x4. 5, Free cheek, 

 X4 (coll. cno/15) ; U.S.N.M. 144658, plesiotypes. 



Figs. 8-20. Aphelaspis lata Rasetti, n. sp 87 



8-10, Dorsal, frontal, and lateral views of cranidium, X4 (coll. cnp/14) ; 

 U.S.N.M. 144659, holotype. 11, Free cheek, x4. 12-14, Pygidia, X4 

 (coll. cnp/14) ; U.S.N.M. 144660, paratypes. 15, Cranidium, x3. 16, 

 Exfoliated cranidium, X3. 17, Pygidium, x4 (coll. cnp/20) ; U.S.- 

 N.M. 144661, paratypes. 18, Pygidium, X4 (coll. cnp/15) ; U.S.N.M. 

 144662, paratype. 19, 20, Cranidia tentatively attributed to the species, 

 X4 (coll. cnr/4) ; U.S.N.M. 144734, paratypes. 



Figs. 21-27. Aphelaspis transversa Rasetti, n. sp 88 



21-23, Lateral, frontal, and dorsal views of cranidium, X4 (coll. cnp/ 

 17) ; U.S.N.M. 144663, holotype. 24, Exfoliated free cheek, x2. 25, 27, 

 Cranidia, X3. 26, Pygidium, x4 (coll. cnp/17) ; U.S.N.M. 144664, 

 paratypes. 



Plate 17 



Figs. 1-5. Cheilocephalus brevilobus (Walcott) 103 



1, Pygidium, x2. 2, Small cranidium, x5. 4, Free cheek, x3 (coll. cnq/ 

 14) ; U.S.N.M. 144707, plesiotypes. 3, Small cranidium, with pygidium 

 of Blountia bristolensis, X3 (coll. cnp/17) ; U.S.N.M. 144708, plesio- 

 type. 5, Small pygidium, x3 (coll. cno/14) ; U.S.N.M. 144735, plesio- 

 type. 

 Figs. 6-11. Cheilocephalus brachyops Palmer 104 



6, Cranidium, x5. 7, Pygidium, X3. 8, Cranidium, X3 (coll. cnw/14) ; 

 U.S.N.M. 144709, plesiotypes. 9, Hypostome, x5. 10, Pygidium, x5. 

 11, Cranidium, X5 (coll. cnx/1) ; U.S.N.M. 414710, plesiotypes. 



