23 I- 



BRITISH PALEOZOIC ASTBROZOA. 



Measurements. — R is 13*5 mm.; r varies from 5 mm. to 6*5 mm. 



Horizon and Locality. — Upper Silurian (Lower Ludlow); Church Hill Quarry, 

 Leintwardine, Salop. 



Remarks.— The presence in the fossils of large areas in some of the inter- 

 radii gives a very strong resemblance to the type. The interradial plates are 

 more irregular than in the type. The adambniacral spines appear to be longer 

 than is usual in other specimens of Palasterina. 



Text-fig. 170.— Oral view of a portion of the disc and arm of Palasterina antiqua (specimen in Royal 

 Scottish Mus.). Ad. u first adambulacral ; Am. u first ambulacral ; F. ]y the cup for the first tube-foot; 

 Ir., interradial plates ; 0., odontophor. x 2o. 



(4) Description of the Small Form from Gutterford Hum (PI. XV, fig. 9; Text- 

 tig. 170). 



Material. — One mould in sandstone in the Royal Scottish Museum, Edinburgh. 

 The oral surface only is shown, and that, rather imperfectly. 



Description. — Text-fig. 170 gives a portion of one arm and the neighbouring 

 interradii. The mouth-angle plates are of the usual Palasterina type, swollen, 

 with a wide gape'and showing the inner coarsely ornamented area. The groove 

 is widely open and has obviously suffered somewhat from post-mortem distortion. 

 The ambulacralia are as in " P. bormeyi." The adambulacralia also are much as 

 in that form. The ornament is very conspicuous and there is no ridge. 



