INDEX 



373 



Dinichthys sp., 282, 289 

 canadensis, 279 

 clarki, 284 



curtus, 200, 284, 287 

 dolichocephalus, 281 

 gouldi, 284 

 gracilis, 284 

 halmodeus, 191, 201, 278 



relations to Brachydirus, 187 

 herzeri, 193, 194, 198, 283 



descended from Coccosteus, 195 



specialization of, 188 

 ingens, 283 

 intermedins, 179, 193, 195, 199, 200, 



284 

 kepleri, 283 

 lincolni, 191, J93, 278 

 minor, 284 

 newberryi, 198, 281 

 precursor, 199, 278 

 prentis-clarki, 284 

 pustulosus, 49, i9//, 198, 278, 281, 28b 



ancestral to D. intermedins, etc., 

 195 

 comparison of, with Neoceratodus, 



196 

 ringueoergi, 281 

 terrelli, 198, 284 



specialization of, 188 

 tuberculatus, 199, 279 (?) 286, 288 

 Dinomylostoma, characters of genus, 



m 



development of, 164 

 Dinomylostoma beecheri, 177, 282 

 Diplacanthidae, advent of, 53 



range of, 112 

 Diplacanthus horridus, 280 



striatus, 280 

 Diplodus, characters of genus, 104 

 Diplodus, sp. ind., 286 



priscus, 101f, 286 



striatus, 105, 286 

 Diplognathus, dentition of, 181 

 Diplognathus mirabilis, 285 

 Diplurus, geological range of, 242 

 Dipneusti, 62, 69 



characters of subclass, 157 



Dipnoans, 62, 68, 157 

 advent of, 62 

 dentition of, 180 

 development of, 164 

 list of, 208 

 relations of, 208 

 Dipterines in Iowa Devonian, 48 

 Dipterus, absence of ossified centra in, 



147 

 characters of genus, 210 

 in Iowa Devonian, 49 

 occurrence of, in Paleozoic, 231 

 relations of, 211 

 two types of, 214 

 Dipterus alleghaniensis, 233, 288 

 angustus, 289 



calvini, 49, 213, 219, 220, 221, 279 

 contraversus, 212, 289 

 costatus, 213, 219, 220, 221, 286 

 digitatus, 213, 219, 221, 286 

 flabelliformis, 213, 221, 223, 224, 288 



a type form, 214 

 fleischeri, 212, 225, 289 

 ithacensis, 212, 213, 282 

 laevis, 223 

 levis, 213 



variety of D. nelsoni, 214 

 minutus, 213, 223, 288 



variety of D. nelsoni, 214 

 mordax, 213, 219, 220, 222, 223, 225, 



286 



relations of, 215 

 murchisoni, 226 

 nelsoni, 213, 221, 228, 224, 288 



a type form, 214 

 pectinatus, 213, 222, 286 

 quadratus, 213, 223 



variety of D. nelsoni, 214 

 radiatus, 212 

 sherwoodi, 212, 226, 289 

 uddeni, 213, 215, 218, 222, 225, 279 

 valenciennesi, 210, 227, 234 

 Dog-fishes, 97 

 Doliodus, 100 



Doliodus problematicus, 275 

 Dollo, L., acknowledgments, 291 



cited, 96, 122, 124, 127, 129, 165, 180. 



208, 237 



