NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE — RASETTI I9 



glabella and the bulging cheeks give it a very peculiar aspect. Among 

 previously known forms it might perhaps be compared with Calo- 

 discus walcotti Rasetti (1952), unfortunately known from a single, 

 somewhat incomplete cephalon. This form also has a pointed, but 

 much longer, glabella, whose posterior portion is extended into a 

 spine. The cheeks, however, have a normal shape. 



BOLBOPARIA SUPERBA Rasetti, new species 

 Plate 3, figure 1 ; plate 5, figures 1-6 



Available material. — A few cephala, small and more or less frag- 

 mentary excepting the holotype which is a large, almost perfect exam- 

 ple. Also a thoracic segment attributed to the species. 



Description. — Cephalon somewhat wider than long, widest at the 

 posterior third, slightly narrowed toward the genal angle, pointed 

 in front. Glabella occupying about two-thirds of the cephalic length, 

 defined by a very deep axial furrow, well tapered, pointed in front, 

 extended into a slender almost vertical spine just in front of the 

 occipital furrow. Lateral furrows short, merging with the axial 

 furrow ; two pairs relatively deep, one additional pair barely visible. 

 Occipital furrow straight, deeper at the sides, but not quite connect- 

 ing with the axial furrows ; occipital ring wider medially, with rounded 

 outline. Cheeks bounded by an irregular line, consisting of strongly 

 oblique posterior border furrow, followed by an almost longitudinal 

 section of the lateral border furrow; at this point the cheeks are 

 widest, then narrow again for a considerable, fairly straight portion; 

 then the outline curves sharply inward in correspondence with the 

 highest part of the bulge and becomes fairly straight, transverse in 

 the anterior portion. The border furrow is well marked all around 

 the cheeks and attains its maximum depth anterolaterally. The bor- 

 der extends into a pair of small, slender spines located somewhat 

 back of the level of the anterior end of the glabella. Two rounded 

 tubercles are located in the wider portion of the lateral border just 

 in front of the posterior border ; as mentioned in the generic diagno- 

 sis, a deep furrow separates here the lateral border, elevated into 

 the posterior tubercle, and the posterior border, carrying the short 

 genal spine. 



Entire surface very densely covered with granules of various sizes ; 

 the largest appear broken at the tip and may represent the bases 

 of short spines. Length of largest (holotype) cephalon 9.0 mm, 

 width 11 .0 mm. 



A peculiar thoracic segment is attributed to the species because 



