208 THE DEVONIAN OF MISSOURI. 



ARTHROPODA 



Class CRUSTACEA 



Subclass Trilobita 



Order Opisthoparia 



Family Goldiidae 



Genus Goldius de Koninck 



Goldius barrandii Hall 1 



Plate 54, figures 27 



Bronteus barrandi Hall, 1859, Pal. N. Y., vol. Ill, p. 350, pi. LXXIII, figs. 1-4, 1861. 



Bronteus canadensis Logan, 1863, Geol. Canada, p. 391. 



Bronteus barrandii Clarke, 1908, N. Y. State Mus., Mem. 9, pt. 1, p. 104, pi. 9, figs. 



12, 13. 



Description — "Pygidium semi-elliptical; line of articulation straight; rudiment of 

 the axis abruptly prominent, nearly twice as wide at its upper edge as the length, show- 

 ing two articulations. Surface around the axis nearly plane, and thence sloping more 

 abruptly, and again becoming nearly flat at the margin; marked by seven ribs on each 

 side the median lobe, which is wider than the lateral ones and gradually narrowing from 

 the base of the axis for one-fifth of its length, below which it gradually expands towards 

 the border without bifurcating; its surface scarcely more prominent than the lateral 

 ribs, and the furrows limiting it not more profound than the adjacent ones; lateral ribs 

 narrow at their origin and gradually expanding towards the margin, the upper one wider 

 at its wider extremity than either of the others. Surface marked by undulating lamellose 

 striae, which are arched upward on the ribs; intermediate spaces covered by fine granu- 

 lations."— Hall, 1859. 



Remarks — Clarke notes: 2 "This species is one of the rarest in the fauna of the 

 New Scotland beds (Helderbergian) in eastern New York and has not been elsewhere 

 found save at the locality here considered. The description was based on a series of 

 pygidia only "but the writer has collected the other parts so that the species is pretty well 

 understood. All New York specimens of the pygidia are of uniformly small size, bear 

 an entire and spineless margin, a broad flat median rib with seven narrow and subequal 

 ribs on each side. We have a single pygidium agreeing with these New York specimens 

 in all details even to size, obtained by me in the St. Alban beds [which 'present a con- 

 geries of 51 species of which fully one-half occurs in the typical Helderbergian faunas 

 (Coeymans of New Scotland) to the southwest.' 3 ] in Cape Rosier Cove [Gaspe]. 



"The name used by Logan as above cited doubtless has reference to this species. 

 We elsewhere note the presence of a large varietal expression of B. barrandii in the fauna 

 of Stewart's Cove, Dalhousie." 



Goldius barrandii is represented in the Missouri material at hand by a part of a 

 pygidium. 



MUt The pygidium was about 15 mm. long, and about 24 mm. wide; that figured by Hall 

 is 12.5 mm. long, and 17 mm. wide; and that figured by Clarke is 9 mm. long, and 12.3 

 mm. wide. 



'"The family name 'Bronteidae' cannot be retained, as de Koninck's term (joldius has 

 priority over Bronteus Goldfuss, a term which was substituted for Brontes of the same author 

 on finding that the latter appellation was preoccupied." — von Zittel's Text-book of Pal., 

 vol. I, p. 720, 1913. 



»N. Y. State Mus., Mem. 9, pt. I, p. 104, 1908. 



•op. Cit., p. 250. 



