PALASTERINA ANTIQUA. 231 



cralia are stout with a coarse, pustulose ornament. Alongside the adambulacralia 

 are the small accessory plates seen in the type species. These are succeeded by 

 almost oblong- infero-marginalia. At the extremity of the arm are a few swollen 

 apical plates similar to those floured in Text-fig. 158, p. 221. 



The mouth-angle plates carry a torus with stout flat spines. The oral surfaces of 

 the adambulacralia are not so rounded as in P. primasva but almost identical with the 

 same surfaces in P. follmanni. The groove in this arm is closed over but is open 

 in other arms (Text-fig. 165). The ambulacralia are closely similar to those in P. 

 primsena, except that they have a slight thickening where they overlap the precedino- 

 plate. An odontophor is visible in the interradial angle. The arms are distinctly 

 petaloid. 



Text-fig. 167. — Drawing of an arm and the base of a second arm of Palasterina antiqua (from specimen in 

 University of Birmingham Museum). Ad. indicates rows of adambulacralia. x 5. 



Measurements. — None of the arms is visible in full length, although it is 

 probable that the arm pointing east is nearly so. This possesses seventeen adam- 

 bulacralia and has R = 16'5 mm., r = approximately 6 mm. 



Horizon and Locality. — Originally given as Lower Wenlockian (Bed C), but the 

 Hamra Limestone is now correlated with Upper Ludlow ; S. Udde, Gotland. 



(2) Description of fhr Specimen from tin- Wenloch Limestone of Dudley {Text-fig. 167)' 



The mouth-region of the specimen seems to be imperfect and mouth-angle 

 plates are not recognisable. In spite of this, there can be no hesitation in referring 

 the specimen to Palasterina. The general form of the arm and the stout, swollen 

 adambulacralia are exactly similar to those of P. primseva, except that they do not 

 seem to show a ridge. The first few adambulacralia are rather irregular in form 

 and remind one of the proximal adambulacralia in Lepidactis wenlocJci (see p. 1 15). 

 The stout adambulacral spines are preserved. Alongside the adambulacralia is the 

 usual row of accessory plates. Beyond these again is a row of swollen infero- 

 marginalia. The plates filling up the interradial areas are rather irregular in shape. 



