216 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



Schondorf states that Gregory's family Palaeophiuridse has no 

 value and is to be merged into the one under discussion. The reasons 

 for this are given beyond under the former family heading. 

 The family contains: 



Tseniaster Billings. Alepidaster Meek. 



Eopliiura Jaekel. Gregoriura Chapman. 



Boliemura Jaekel. BundenlacJiia Stiirtz. 



Palsdura Jaekel. Pdlseopliiomyxa Stiirtz. 



Protaster Forbes. 



Genus T^^NIASTER Billings. 



Plate 36, figs. 1-3. 



Tseniaster Billings, Geol. Surv. Canada, Can. Org. Rem., dec. 3, 1858, p. 80. — 

 Chapman, Canadian Journ., n. ser., vol. 6, 1861, p. 517. — ^Wright, Mon. 

 British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palseontogr. Soc. for 1861), 1862, 

 pp. 24, 34.— Hall, Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 300; 

 rev. ed., 1868=1870, p. 338.— Zittel, Handb. Pal., vol. 1, 1879, p. 445.— 

 Stxjrtz, N. Jahrb. fiir Min., etc., 1886, vol. 2, p. 150; Palseontographica, vol. 

 32, 1886, pp. 78, 83.— Miller, N. Amer. Geol. Pal., 1889, p. 285.— Gregory, 

 Geol. Mag., dec. 3, vol. 6, 1889, p. 26. — Sturtz, Verh. naturh. Ver. preusa. 

 Rheinl., etc., vol. 50, 1893, p. 20. — J. F. James, Journ. Cincinnati Soc. Nat. 

 Hist., vol. 18, 1896, p. 138.— Gregory, Proc. Zool. Soc. London for 1896, 1897, 

 p. 1035; Treat. Zool., vol. 3, Echinoderma, 1900, p. 250.— Spencer, Mon. 

 Brit. Pal. Asterozoa, pt. 1 (Palseontogr. Soc. for 1913), 1914, pp. 8, 19. 



Tseniura Gregory, (not Tseniura Miiller and Heule 1837, sting-ray), Proc. Zool. 

 Soc. London for 1896, 1897, p. 1035. 



Original description of Tseniaster. — "Generic Characters. — Body 

 deeply stellate; no disk [there is a disk] or marginal plates; rays 

 long, slender, flexible, and covered with small spines; two rows of 

 large ambulacral pores; adambulacral plates elongated and sloping 

 outward so that tliey partly overlap each other; ambulacral ossicles 

 contracted in the middle, dilated at each end. Generic name from 

 tainia, a riband." 



Genolectotype (the first species of Billings is here selected as the 

 genolectotype) . — Palxocoma spinosa Bilhngs. 



RemarTcs. — Hall restudied the type-material of Txniaster and 

 records his observations as follows : 



''In reviewing the characters of Protaster and Eugaster, I became 

 satisfied that there was an intimate relation between these and 

 Tseniaster of Bilhngs, and in order to satisfy myself on this point, 

 I have * * * received from Sir William E. Logan, permission to 

 examine specimens of Txniaster spinosus and T. cylindricus. 



"An examination of the specimen illustrated in fig. 3 (ut sup.) 

 reveals what I conceive to be a disk not at all unhke the disk of Prot- 

 aster, but less extended than in the Lower Helderberg species. The 

 structure of the ray is precisely of the sarrie character as the ray of 



