1028 



ba. i. w. gAegoey oU TilE otiSsiriOATioN [Dec. 15, 



Keithrodon, 80. 

 Eeithrodontomye, 77. 

 KLeithrosoiuius, 3. 

 Ithipidomys, 72. 

 Bhizomys, 99. 

 Rhombomys, 31. 

 Bbyncliomya, 2.'). 

 BouioroluguB, 158. 

 Saccostouius, "14. 

 Soaptei'oniys, 82. 

 Sehizodon, 125. 

 Sciuropterus, 12. 

 SciuruB, 5. 

 Sigmodon, 76. 



Sipbneus, 98. 

 Sitomya, 71. 

 Smintlius, 113. 

 Spalacopua, 126. 

 Spalax, 101. 

 Spermopbilua, 7. 

 Stcatomya, 37. 

 Synaptuiuya, 94. 

 Synetlieroa, 140. 

 Tachyoryotoa, 100. 

 Tamiaa, 6. 

 Tlioraoraya, 103. 

 TbricUomya, 133. 

 Tbrinacodua, 130. 



Tbryonomya, 141. 

 Triaulacodua, 141. 

 Trichya, 144. 

 Tylomya, 73. 

 Typblomya, 21. 

 Ui'Omya, 58. 

 Vandoloiiria, 48. 

 Voaporiuuia, 71. 

 Xenomya, 89. 

 Xeromya, 23. 

 Xerua, 4. 

 Zapua, 114. 



7. On the Classification of the Palseozoic Echinoderms of 

 the Group Ophiuroidea. By J. W. GREGoftYj D.Sc., 



F.Z.S. 



[Eeceived Norember 5, 1896.] 



For fifty years after Forbes, in 1840 [3. p. xiv], proposed to 

 rank the Ophiuroidea as one of the classes of Echinoderuia they 

 were divided into two groups — the Ophiura3 and Buryala> of 

 Joh. Midler, the Ophiuridoe and Euryalida) of Th. Lyman. In 

 1867 Dr. Axel Ljungman [7] divided the first group into six 

 famiUes (the Ophiodermatida;, Ophiolepididae, AmphiuridiB, Ophio- 

 myxidse, Ophiocomidse, and Ophiothricidffi), but Mr. Lyman [10], in 

 his description of the Ophiurids collected during the ' Challenger' 

 Expedition, made no use of family divisions. He simply divided 

 the Ophiuridfe into three groups, of which the first two were 

 unnamed, and the third was merely described as comprising 

 "Astrophyton-like Ophiuroids." Hence Lyman's great monograph, 

 the richest mine of information in the wliole range of literature on 

 the Ophiurids, did not contribute so mucli to their classification as 

 to our knowledge of their anatomy. 



As neontologists were in difficulties owing to the lack of a 

 satisfactory arrangement of the recent species, palsBontologists 

 were naturally in a worse state ; for the anatomical characters of 

 the fossil Ophiurids had been in but few cases satisfactorily deter- 

 mined. Wo have only to refer to Wright's introduction to the 

 British Jurassic Starfish [20], or to Liitlfen's [9. pp. 70-75, 78] 

 heroic attempt to improve the generic nomenclature of the Neozoic 

 Ophiurids, to see how unscientific the existing systems were. In 

 1886 and 1890, Herr B. Stiirtz, in two important memoirs [15, 16], 

 described the anatomy of several genera from the Devonian of 

 Bundenbach, in the Bavarian Pfalz. The fossils are pseudomorphs 

 in iron pyrites ; owing to the exceptional preservation of the 

 specimens and the skill and patience with which Stiirtz dissected 

 them from their clay-slate matrix, their anatomical structure was 

 well displayed. Stiirtz's two papers are a great advance on any 

 previous work dealing with Palaiozoie Ophiurids ; but the author 



