REPORT OF THE STATE PALEONTOLOGIST I903 1 53 



limestone) of eastern New York (D. hamatus Conrad) and 

 from the equivalent horizon Etage G, of Bohemia ( D . m o n - 

 strosus Barrande sp.). The species from Cap Barre (D. 

 limenarcha) is represented only by an incomplete cephalon 

 but it is rarely that any other part of the genus has been observed in 

 any of its occurrences. It was a species larger than the New York 

 form and perhaps even larger than the Bohemian. Its elongate, 

 subconate middle lobe is well delimited by a deep nuchal furrow, the 

 lateral lobes are separated by a shallow transverse or oblique groove, 

 while the axial diameter of the occipital ring from the base of the 



M '-^ 



Dicranurus limenarcha 



central lobe to the fork of the spine is relatively less than in D . 

 hamatus. The free cheeks were attached to this specimen, but 

 they have not been preserved except along the sutures. The great 

 neck spines are highly divergent and very heavy. Barrande gave 

 the angle of divergence in D. monstrosus as 60°, in D . 

 h a m a t u s it is 45°, in D . limenarcha it is 80°, measured from 

 the central occipital tubercle as apex, axially for one third of the 

 length of the spines. These spines are curved outward, downward 

 and back, and probably made a deep recurvature as in the other 

 species, though they are not preserved at the tips. On their proximal 

 extent is a low median depression. The surface of the head is 

 covered with acute pustules scattered sparsely with very much finer 



