26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, I28 



of the glabella with the size of the individual, as clearly shown by the 

 three illustrated cranidia. Note also the resemblance of the smallest 

 cranidium (pi. 4, fig. 15) to Onchocephalus, species undetermined 

 No. 2 (pi. 3, fig. 22). 



Occurrence. — Boulder G-24, Grosses Roches. 



73;/)^.?.— Holotype : U.S.N.M. No. 123880. Paratypes: U.S.N.M. 

 No. 1 23881. 



BICELLA Rasetti, new genus 



Description. — Glabella tapered, straight-sided, sharply truncated 

 in front, defined by a deep dorsal furrow. Glabellar furrows shallow ; 

 occipital furrow well impressed ; occipital ring expanded medially. 

 Frontal area poorly differentiated into preglabellar field and a wide 

 (sag.), swollen border. Palpebral area convex and somewhat up- 

 sloping, less than half as wide as the glabella. Ocular ridges strong, 

 extended into prominent, convex palpebral lobes situated at the level 

 of the glabellar midpoint and one-third as long as the glabella. Pos- 

 terior limbs as wide (tr.) as occipital ring; distal portion equal to 

 proximal portion. Marginal furrow deep but not attaining the end. 

 Anterior and posterior facial sutures similar to Periomma. 



Type species. — Austinvillia bicensis Resser. 



Remarks. — The type species was assigned to Austinvillia on the 

 basis of two imperfect cranidia available to Resser. Much better 

 material now extant shows that this form bears little resemblance to 

 Austinvillia and cannot be assigned to any described genus. Bicella 

 is probably closest to Periomma, from which it differs in the lack of a 

 deep anterior marginal furrow, narrow palpebral area, and larger pal- 

 pebral lobes. Bicella differs from Austinvillia in the convergence of 

 the anterior facial sutures, rounded anterior outline of the cranidium, 

 narrowness and convexity of the palpebral area, larger palpebral 

 lobes, deeper dorsal furrow, truncated glabella, and posterior mar- 

 ginal furrow not extending to the end of the posterior limb. 



BICELLA BICENSIS (Resser) 



Plate I, figure 7; plate 4, figures 1-7 



Austinvillia bicensis Resser, Geol. Soc. Amer. Spec. Pap. 15, p. Cr, pi. 3, figs. 



6, 7, 1938. 

 Austinvillia bicensis Resser, Rasetti, Amer. Journ. Sci., vol. 243, p. 317, pi. 2, 



figs. 1-4, 1945. 



Available material. — The type lot includes the two syntypes, both 

 incomplete, exfoliated cranidia. About a dozen additional cranidia 



