PLATE IV'— Coiuinaeil. 



KUTORGIXA. Billings. 



Page ao. 

 KUTOKGINA CINGULATA, BillillgS. 



Fig. 10. The ped'u:le-val\e of an example with a low, scarcely incurved l)eak. X 2- 



Fig. 11. The brachial valve. X 2. 



Fig. 12. Profile of a peilicle-valve from which the shell is largely removed ; showing the degree of incurv- 

 ature. X 3. 



Fi'^. 13. A pedicle-valve with a strongly incurved umbo; drawn from an internal cast. X 3. 



Fig. 14. Profile of the same. X 3. 



Fiu". li). A brachial valve : drawn from a gutta-percha impression of a natural mould of the exterior. 

 Natural size. 



Fi"'. IS. The interior of a In-achial valve ; showing the radiate ornamentation of the surface and the faint 

 muscular ridges near the beak. X 2. ' ' ' ■ ■ . - ■ 



Fi". IT. A brachial valve in which the cardinal margin is not transverse, as in the other examples fig- 

 nved, but is strongly reenti'ant. X 2. 



Georgia group. Swanton, Vermont. 



KuTORGiXA Latourensis, MuUIr-w. 



Fig. 18. A i>edicle-valve ; drawn from a gutta-percha cast from a natural mould of the exterioi-. X U. 

 Fig. 19. Profile of the same. X tj- .m .u ■ 



Fin-. 20. Cardinal view of the same; showing the open triangular fissure. X 0. 

 St. John group. Portland, New Brunswick. 



MESOTRKTA, Kltouga. 



Page 109. 

 MeSOTRETA TENTORIUM, KutolWl. 



Fi"-. 21. The pedicle-valve ; copied from Kitouoa's work, Uel)er die Brachiopoden-faniilie der Siphono- 

 treta"^, yl. vii, fig. 4c. 



Lower Silurian, liussla. 



SIPHONOTRKT.V, Vkrnkuil. ' 



Page no. 

 SiPHONOTRETA UNGUICULATA, Venieilil. 



Fig. 22. Cardinal portion of the pedicle- valve; showing the inner extension of the sipho, which is appar- 



rently atrophied and ca;cal. 

 Fig. 23. A similar portion of another valve in which the sii)ho is Ojien. 



(KuTOKGA, (tp. ait., pi. vi, fig. 3, a, b.) 

 Fig. 24. A portion of the shell near the anterior margin, much enlarged to show the tubular structure, the 

 epidermal layers and the mode of oi'igin of the hollow .spines. 

 (KuTORfiA, op lit., pi. vi. fig. 2c.) 

 Figs. 25, 2G. The interior characters of both valves as given by D.^^vidsom. 

 (Geological Magazine, 1877, pi. ii, figs. 9, 11.) 



SCHIZAMBOX, Walcott. 



Page 113. 

 SCHIZAMBON TYPICALIS, Willcott. 



Fig. 27. The interior of a pedicle-valve ; showing an oval foramen with the groove or depressed track, and 

 diverging lateral muscular ridges. X 5. 



Fig. 28. The exterior of a brachial valve; showing the radiating ;inil concentric stri.'e. In this specimen 

 the snrfai^e appears finely granulose. the gr.anulations jirobably being the lia-ses of minute 

 spinules like those represented by Mr. Walcoit {Pal.tont. Eureka Dist., pi. i, fig. 3d). 



Fig. 29. The interior of a brachial valve ; showing the outline of the muscular area and its subdivision 

 by diverging ridges. X 5. 



Fig 30. Another interior of a brachial valve, ditt'eriiig from the foregoing in the less conspicuous division 

 of the muscular area. The inner jiair of diverging i-idges terminate anteri(n-ly in deeply col- 

 ored, oval ai'eas, which are too strongly elevated in the figure. X o. 



bowel- portion of the I'ugouip groii|i. Kiirtka District, Nernda. 



