5 68 



NEW YORK STATE MUSEUM 



Dictyonema robustum, 131. 



scalariforme, 52, 53, 127, 131, 153-55- 



explanation of plate, 490. 



figures, 154. 

 spiniferum, 13, 48, 127, 131, 151. 



explanation of plate, 490. 



figures, 151. 

 splendens, 56, 58, 131. 

 subretiforme, 52, 55, 127, 132, 162-64. 



explanation of plate, 492. 

 tenellum, 56, 132, 158, 159, 162. 

 tuberosum, 225. 

 venustum, 155. 

 websteri, 56, 132. 

 Didymograptus, 15, 19, 25, 67, 68, 71, 72, 



107, 109, 117, 120, 128, 134, 233, 247, 



260, 291, 450, facing p. 66. 

 sp., 139. 



acutidens, 107, 134. 

 arcuatus, 134. 

 bifklus, 134, 418. 



zone, facing p. 9, 66. 

 bipunctatus, 134. 

 caduceus, 118, 134. 



var. nanus, 7^, 77, 134. 

 constrictus, 134. 

 convexus, 134, 248, 249, 250. 



figures, 249. 

 cuspidatus, 134. 

 divaricatus, 296. 

 elegans, 128, 134, 255-56, 312. 

 ellesae, 134. 

 euodus, 25, 134. 

 extensus. 134, 135. 

 extenuatus, 134. 

 filiformis, 134. 

 forcipiforinis, 134. 



zone, facing p. 9. 

 furcillatus, 134. 

 geminus, 418. 



zone, facing p. 9. 

 gibberulus, T07. 

 gracilis, 134, 254. 



Didymograptus birundo, 134. 

 incertus, 134. 

 indentus, 134. 



var. nanus, 134. 

 moffatensis, 310. 

 nanus, 72, J 34- 

 nicbolsoni var. planus, 134. 

 nitidus, 134. 

 patulus, 134. 

 pennatulus, 134. 

 perflexus, 134. 

 rectus, 128, 134, 256. 

 Sagittarius, 25, 134. 248, 250, 426. 

 sagitticaulis, 13, 16, 19, 22. 48, 128. 134, 

 135. 247-51, 252, 254, 268. 310. 335. 

 explanation of plate, 516. 

 figures, 249. 

 serratulus, 13, 16, 18, 22, 35, 48, 128. 134, 

 247- 251-53. 

 explanation of plate, 516. 

 figures. 252. 

 var. juvenalis, 253. 

 figure, 252. 

 sextans, 306. 

 similis, 134, 251. 

 spinosus, 74, 75. 134. 

 subtenuis, 13, 16, 48, 72. 104, 128, 134. 

 247, 250. 252. 253-55, 335. 

 explanation of plate, 516. 

 figures, 105, 254. 

 cf. superstes, 134. 

 tenuis, 134, 253. 

 tornquisti, 134. 

 Dimorpbograptus, 440. 

 Diplograptidae. 67, 68, 103. 104. itq, 126, 

 129. 339. 

 figures, 88. 

 Diplograptus, <), 18. 27. 30, 40. 67. 68, 72, 

 74, 80. S6, 87, 04, oo. 103. 115. no, 

 120, T22, T23. 125, 126, 129, 137. 

 233. 339-4L 377. 300. 300. 401, 402, 

 403, 404. 417. 447, 448. 440. 450, 

 462, 466, 46c), 473, facing p. 104. 



