164 



BRITISH PALEOZOIC ASTEROZOA. 



1. Sub-family Protarthrasterinaj, nova. 

 Diagnosis. — Arthrasteridae with many rows of apical plates. The inner 

 rows have paxilla-shafts as transverse ridges. The outer rows have columnar 

 paxilla-shafts. 



Genus PROTARTHRASTER, novum. 

 Generic Characters. — As those of the sub-family. 



1. Protarthraster longimanus (Whidborne). Plate XIII, figs. 3 — 5; Text-figs. 



104—108. 



1890. Palieaster longimanus, Whidborne, Proc. Geol. Assoc, vol. xiv, p. 376. 



1898. ,, „ „ Mon. Devonian Fauna S. England, vol. lii (Palaxmtogr. 



Soc), pp. 204-215, pi. xxvi, figs. 1-4 ; pi. xxix, fig. 3. 



Material. — Six specimens are known, four in the Museum of Practical Geology, 



104 



105 



X X 



Text-fig. 104. — Wash drawing of a portion of the apical surface of Protarthraster longimanus. C, centrale ; 



R., radialia ; X., adradialia of first and second series ; X. tX., fused adradialia (proximal interradial) . x 6. 

 Text-fig. 105. — Cross-section through the arm of Protarthraster longimanus. Ad , adradialia ; I.M., infero- 



marginalia ; P., radialia. x 20. 



Jermyn Street. These include the holotype (71 G3 and its counterpart 71 04) 

 figured by Whidborne, pi. xxvi, figs. 1, 2, and figured here, PI. XIII, figs. 3, 4, and 

 in the Text-figures ; specimen 71G2 figured by Whidborne, pi. xxvi, fig. 3, and 

 figured here, PI. XIII, fig. 5, and two specimens not figured here nor by Whid- 

 borne. The remaining two specimens are in the Sedgwick Museum, Cambridge. 

 They are both figured by Whidborne, pi. xxvi, fig. 4, and pi. xxix, fig. 3 respec- 

 tively, and not re-figured here. 



Holotype (Plate XIII, figs. 3, 4; Text-figs. 104— 107).— The holotype is at first 

 sight so different from the other specimens that it almost looks like another species. 

 Its disc is raised and the arms stretched out in straight lines from it. Casts of the 



