PLATE 14 



Figs. Porambonites teretior (Eichwald) 



I, 2, 4, 5, 10. — Dorsal, anterior, posterior, ventral, and lat- 

 eral views of a rather smooth, attenuate type. 

 Ordovician (Mohawkian, Kuckers), near Jewe, Es- 

 tonia. Cat. No. S 1520. x 1. 



Porambonites deformatus (Eichwald) 

 6, 7, 9. — Posterior, ventral, and lateral views of a coarsely 

 pitted, attenuate type. 

 Ordovician (Mohawkian, Echinosphserites Is.). 

 Popovka, near Leningrad, Russia. Cat. No. S 1528. 

 X 1.5. 



Porambonites baueri Noetling 

 8. — Dorsal interior, showing great internal thickening of 

 brachiophore (spondyloid) plates. 

 24. — Dorsal interior of a gerontic individual, showing 

 greatly thickened brachiophore plates. 

 Ordovician (Mohawkian, Jewe, DJ, near Jewe, 

 Estonia. Cat. No. S 1529. x 1. 



Porambonites gigas Schmidt 

 14. — Posterior view, showing resorbed beaks. This condi- 

 tion of the beaks indicates that the pedicle persisted 

 throughout the life of the animal. 

 Ordovician (Richmond, Lyckholm, Fi), Kurkul, 

 Estonia. Cat. No. S 1518. xO.5. 



Porambonites reticulatus Pander 



3, 11-13. — Posterior, dorsal, ventral, and lateral views of 

 the same individual, showing suborbicular outline and 

 characteristic ornamentation. 

 15. — Anterior view of another individual, showing deep 

 ventral sulcus and long tongue. 

 Ordovician (Chazy, Walchow), Iswos on Walchow 

 River, Russia. Cat. No. S 1 532. x 1. 



Figs. Porambonites reticulatus Pander — Cont. 

 29. — Enlargement of a portion of fig. 11, to show ornamen- 

 tation in greater detail. 



Ordovician (Chazy, Walchow), Iswos on Walchow 



River, Russia. Cat. No. S 1532. 



Porambonites schmidti Noetling 



20, 27. — Views of ventral interior, the former tipped for- 

 ward to show better the dental plates. These plates 

 are discrete but in old forms may unite by secondary 

 deposition on their sides and the floor of the valve. 



21,28. — Two views of a dorsal valve belonging to the 

 ventral one above. In fig. 28, the reader is looking 

 directly into the shell and the short brachiophore 

 plates are not visible but the sockets are clearly dis- 

 cernible. In fig. 21, the front of the shell is tipped 

 forward to permit a view of the brachiophore plates, 

 which are also discrete. There are no structures in 

 either of these two shells or in the genus linking them 

 to the Pentameridx. 

 Ordovician (Mohawkian, Jewe, DJ, Spitham, Es- 

 tonia. Cat. No. S 1530. x 1. 



Lycophoria nucella (Dalnian) 



16, 18. — Ventral interiors, showing discrete dental plates. 

 22, 23. — Dorsal interiors, showing cardinal process. 



30. — Same as fig. 22, enlarged three times to show greater 

 detail. Cardinal process complete and uninjured in 

 any way, not forked as Hall and Clarke assert. Com- 

 pressed brachiophore plates visible, and also short 

 brachiophores. 

 Ordovician (Chazy, Kunda). Popovka, near Len- 

 ingrad, Russia. Cat. No. S1515. x 1.5 (except 

 fig. 30). 



17, 19, 25, 26. — Lateral, ventral, dorsal, and posterior views 



of a complete individual, showing contour, profile, 



and ornamentation. 

 Ordovician (Chazy, Kunda, B^), Popovka, near 

 Leningrad, Russia. Cat. No. S 1516. x 1.5. 



222 



