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BRITISH PALAEOZOIC ASTEROZOA. 



material. The odontophor is a very prominent flat plate, shaped somewhat like a 

 kite. Its proximal edges are convex and its distal edges slightly concave. Each 

 proximal edge carries a month-angle plate and two adambnlacralia. The month- 

 angle plates are high, narrow, and project well into the month-cavity (see 

 Text-fig. 143, p. 203). Proximally the triangular depression for the inter- 

 dental muscle shows as a deep depression. If this muscle be relaxed, as in some 



Text-fig. 154. — Slightly reconstructed view of an arm and a portion of the disc of Schuchertia wenlocki. 

 Ad., adanibulacral ; Am., ambulacral ; I.M., infero-marginal ; M ., madreporite ; M.P., mouth-angle plate ; 

 U., odontophor. x 6. 



specimens, the mouth-angle plates appear strongly divergent (PI. XV, fig. 3). A 

 fringe of slender spines projects from the mouth-angle plate into the mouth-cavity. 

 The first two pairs of ambulacralia are small. By inference we may suppose that 

 the proximal tube-feet were also small. 



These proximal pairs of ambulacralia do not meet across the middle line but 

 form divergent arms of a V. The first two pairs of adambulacralia are also 



