PLATE Vc. 



(Ficuvesl,2, il-ls, i'l-tl. l)v U. I'. Will n i i.i.r>; I. ."■. W, W-IT, by K. Kmmi>n>, .;, J(i J I, In .1. €. iM(:(;(>N-Ni;i,i..i 



Legend. A- Deltidium. !i- Aulerior adductor scais. 



t. Teeth. ^'- Postei'ior adductor .scars. 



b. Sockets. r. Diductor seal's, 

 fp. C'l-iiral i^lates. o. Ovarian mai-king^. 



j. Cardinal process. v. Vascular markinics. 



c. Crura. 



DALMANKLLA, nom. no v. 



I'ajfC -205. 

 OuTlIIf* EMACERATA, H;ill. 



Figr. 1. The central cardinal ijortinn of the interior of a brachial v.-dvc; showing- the processes and 



muscular imprints. X 3. 

 Fig-. "2. The exterior of a brachial valve. 



Hudson River group. C'uicinimti, Ohio. 

 For further illustration, see Palfeontology of Ohio, Voliuae I, plat(^ viii. Htrs. I. 2. 



Okthis jSIeeki, Miller. 



Fig. 3. The interior of a brachial valve ; showing the cardinal process, crura and muscular scars. The 

 apparent impressions in the umbo-lateral regions are due to abnormal thickening of the test. 

 X 2. 



Hudson River group. Spri>i.(f VaUey, Minnesota. 



Okthis Stonensis, Saffonl. 



Fig. 4. Protile of a specimen w iih valves conjoined. X 2. 



Fig. :'). A vie-w of the pedicle-valve of the same .specimen ; showing the alternating, fasciculate character 

 of the radiating strise. X 2. 



Orthis sub;equata. Connid. 

 Fig. 6. A view of the brachial \-alve ot the original specimen ; showing the area and foramen of the op- 

 posite valve. 

 Figs. 7, 8. Profile and cardinal views of the same. 

 Fig. 9. The articular and muscular area of the lirachial valve. X '^■ 

 Figs. 10, 11. Interiors of the pedicle and brachial valves. 



Trenton horizon. Mineral Point, Wisconsin. 

 For further illustration, see Palseontology of New York, Volume I, plate xxxii. tig. 2. 



Orthis peuveta, Coiiftnl. 



Fig. 12. View from the brachial valve of the origiiui! specimen. 

 Figs. 13, 14. Brachial and profile views of a larger individual. 



Ti'enton horizon. Mineral Point, Wviconsin. 

 For further illustration, see Palaeontology of New York, Volume I, plate xxxii, tig. 5. 



Orthi.s elegantula. D.iliu:m. 



Figs. 15, 16. Opposite sides of the same individual ; showing the form of the species as occnriing at this 



locality. 

 Fig. 17. The interior of a pedicle-valve, somewhat enlarged. 

 Fig. 18. The interior of a brachial valve ; showing the muscular impressions and articidar processes. X 2. 



Niagara group. Waldro7i, Indiana. 

 Fig. 19. Cardinal view of the centi-al poi-tion of the brachial valve : showing the composition of the cardi- 

 nal process, the great elevation of the crural plates and crura, and their furrowed or crenulated 

 outer walls. X 3. 



Ujiper Silurian limestone. Island of Gotland. 

 For further illustration, see Davidson, Silurian Br.achiopoda, pi. xxvii, figs. 1-9 ; H.it,i., Twenty- 

 eighth Rept. N. Y. State Mus. Nat. Hist., pi. xxi, figs. 11-17. 



