166 BRITISH PALEOZOIC ASTEROZOA. 



fcion of former regular quadrilateral edges of the mould. The paxilla-shafts of the 

 first and second rows of adradialia are always transverse ridges. 



There are a further three rows of small adradialia, only seen in side view, 

 carrying short columnar paxilla-shafts. Remains of the spines which were 

 originally carried by the paxillae are to be seen between and occasionally on the 

 plates. I have not been able to identify a madreporite. 



In oral view the infero-marginalia are clearly seen. They are not pushed on 

 to the apical surface as in Urasterella. Each ossicle has a transverse ridge. The 

 adambulacral ridges are also clearly seen. The mouth-angle plates are not very 

 distinct in this specimen. There is a large ridged odontophor in each inter- 

 radius. 



Specimen from Baggy Point (Plate XIII, fig. 5 ; Text-fig. 108). — The arms in 

 this position have been somewhat disturbed after death. The various views 

 obtained enable me to add to the details given above. The mouth-angle plates are 

 not as in Urasterella, but have a distinct proximal hollow which carried large and 

 prominent spines. The groove is open in many portions of the arm. The adambula- 

 cralia are seen to be exactly as in Urasterella. The exposed ambulacralia are very 

 similar to those of U. ruthveni. The left arm of the photograph shows a good side 

 view of the three outer small rows of adradialia. These carry very short columnar 

 paxilla-shafts. 



The remaining specimens only confirm the details already given. 



Measurements. — Specimen 7162 nlone enables one to give the relative length 

 of the major and minor radii ; R : r : : 20 mm. : 2 mm. The holotype has r = 

 2 mm. The arms are broken off short. The specimen figured by Whidborne, 

 pi. xxix, fig. 3, is about half the size of the above specimens. 



Horizon ami Locality. — Upper Devonian (Pilton Beds) of North Devon. 



2. Sub-family Calliasterellinse, nova. 



1910. Calliasteridiv, Schondorf, Jahrb. nassauisch. Ver. Naturk., Wiesbaden, vol. 63, p. 251. 



1914. Calliasterellidse, Seliucliert, Fossilum Catalogus, Auimalia, pt. 3, p. 7. 



1915. „ Schuchert, Bull. 88, U.S. Nat. Mus., pp. 162, 163, 190. 



Dio i/Hosis. — Arthrasteridas with three rows of apical plates (one row of radialia 

 and two rows of infero-marginalia). These rows have paxilla-shafts in the form 

 of strong transverse ridges. Odontophor with strongly indented sides. 



The sub-family does not contain any known British species. Its one repre- 

 sentative, Galliasterella mint, Trautschold, from the Russian Carboniferous, occurs 

 at the same horizon and locality as Urasterella montana (see p. 147). A full 

 description of the form was given by Schondorf (65, pp. 327 — oo7, pi. xxiii, 

 figs. 2 — 5, pi. xxiv, figs. 1 — 18), who thought that the form was a Cryptozonate 



