350 



Dr. J. W. Gregory — On Pakeozoic Starfishes, 



About 25 large, oblong adauibulacral plates on eacli side of each 

 ray. The adambulacrals bear small tufts of about three spines, 

 and single spines occur on the plates of the actinal intermediate 

 areas, which plates are numerous. 

 Distribution. 



Ludlow Shales : Leintwardine, Shropshire. 

 Figures. 



PI. XVI, Figs. 2a and h. Abactinal and actinal views of specimens 

 in the Geological Survey Collection. 



Fig. 1, abactinal surface of part of the disc and one ray, x 3 dia. 

 Fig. 2, actinal view of a ray, x 4 dia. Figs. 3a and h, abactinal 

 and actinal views of distal part of one ray. 



si V 





Tig. 



Fig. 1. Fig. 2. 



Falceasteo-ina Boimcyi. Ludlow Shales ; 

 1. — Abactinal surface of oue rav, x 3 dia. 



Leintwardine. 

 Fig. 2. — Actinal surface, 



4 dia. Figs. Za and h. — Abactinal and actinal views of distal end of ray. 



Affinities. 



This species has hitherto been included in P. primceva, the type 

 species of the genus, from which it dijEFers by having shorter and 

 blunter rays, more numerous actinal interbrachial plates, and more 

 adambulacral plates in each series ; the character of the abactinal 

 ray plates is also different in the species, the longitudinal series 

 being widely separated at the proximal end of the rays in P. Bonneyi. 



The species is of interest, as the structure is better preserved than 

 in the type of the genus, and thus we are largely dependent upon it 

 for our knowledge of the generic characters. These are well shown 

 in the accompanying illustrations, which are prepared from the 

 proofs of some unpublished drawings by J. W. Lowry. 



2. SCHCEXASTER, Meek & Worthen, 1860. 



Falaasterina, subgenus Schajiaster, Meek ct "Worthen, 1860 : Proc. Acad. Nat. Sci. 



Pliil., 1860, p. 449 ; and 1860, Geol. Surv. 111., Palreont., vol. ii, p. 277. 



Type Species. — Pcdceasterina (Schoenaster) fimbriata, Meek & 

 Worthen, 1860. Op. cit., p. 449; and 1866, op. cit., p. 278, 

 pi. xix, fig. 7. Sub-Carboniferous : Illinois. 



