G. R. Wieland — Upper Cretaceous Turtles. 433 



As clearly shown in the figures, A. tar dies was of robust 

 oval form with marked depth over the inguinal region, and a 

 distinct flanging of the nuchal region which gives the carapace 

 a very symmetrical to ornate appearance. The rib capitulse 

 are diminutive. The medium-sized and heavy plastron with- 

 out fontanelles is strongly interlocked by suture with the mar- 

 ginals, and the axillary buttress extends forward to the 3d, the 

 inguinal buttress, back to the 8th marginal, as in Adoeus. 



Figure 4. — Agomphus tardus. Dorsal view of the carapace. Drawn from 

 the type with parts actually present stippled. N, nuehal ; MI, 1st marginal. 

 1-7 and 9, the neuralia ; P, pygal ; PM, pygal marginal ; I-VIII, the respec- 

 tive pleuralia. 



The most curious single feature is the complete perforation of 

 the first marginals by the costiform processes of the nuchal. 

 (Cf. figure 6.) The outlines of the transverse sections of the 

 several elements as shown in the supplementary figures 6 and 

 7, in connection with the measurements may render more 



