NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE — RASETTI 41 



Discussimi. — The reference to the genus is chiefly suggested by 

 the considerable length of the preglabellar field and the presence of 

 a preglabellar ridge ; however, these may be juvenile features. The 

 present form is almost identical with an immature cephalon attributed 

 to Paedeumias from a conglomerate boulder near Levis, Quebec, 

 figured by the writer (Rasetti, 1948, pi. 2, fig. 5). If this cephalon 

 is conspecific with the larger one from the same locality (Rasetti, 

 1948, pi. 2, fig. 6), the reference to Paedeumias seems well founded. 

 Comparison with immature cephala of Elliptocephala asaphoides 

 shows that the present species differs in several respects. 



Disposition of material. — Figured specimens: U.S.N.M. 146036. 



PAEDEUMIAS?, species undetermined No. 2 

 Plate 12, figures 19, 20 



Available material. — A few, incomplete cephala. 



Description. — Glabella flat, hardly elevated above the cheeks, 

 defined by a shallow axial furrow only in the portion corresponding 

 to the posterior lobe ; the two preceding lobes extend, undifferentiated 

 from the cheek, as far as the palpebral lobe. Glabella tapered, with 

 frontal lobe considerably narrower than the posterior lobe and the 

 occipital ring. Three pairs of glabellar furrows increasing in depth 

 rearward, fairly well impressed at the sides, fading out medially, 

 oblique and approximately parallel to each other. Occipital furrow 

 of identical character ; occipital ring as long as the last glabellar 

 lobe, bearing a node. Palpebral lobes broad, scarcely elevated, pos- 

 teriorly reaching the level of the midlength of the occipital ring. A 

 narrow rim, set off by a narrow furrow, encircles the palpebral lobe. 

 All the cephala are broken at the outer edge of this rim, i.e., at the 

 upper boundary of the visual surface of the eye, where the facial 

 suture is located in opisthoparian trilobites ; the remainder of the 

 pleural portions of the cephalon is completely missing. The area 

 comprised between the glabella and the palpebral lobe is very narrow, 

 and defined only posteriorly as previously indicated. Length of gla- 

 bella plus occipital ring 5-6 mm. 



Occurrence. — Collection cs-4. North Chatham. 



Discussion. — This form has features unusual among the Olenellids 

 of the late Lower Cambrian, especially the tapered glabella and the 

 well-defined narrow rim around the palpebral lobe. It cannot be 

 identified with any described species known to the writer. 



Disposition of material. — Figured specimens: U.S.N.M. 146037. 



