Il8 RESEARCH IN CHINA. 



obliquely inward and backward; the posterior pair outlines a rather large postero- 

 lateral lobe, which is confluent with an oval-shaped lobe that interrupts the dorsal 

 furrow and on one side merges into the fixed cheek ; a second pair of furrows outlines 

 a small, narrow lobe that is scarcely separated from the fixed cheek by the dorsal 

 furrow; occipital furrow narrow, transverse; occipital ring broken away; dorsal 

 furrow slightly outlined in front and at the antero-lateral angles of the glabella, 

 and practically non-existent back of that at the sides, owing to interruption by 

 the merging of the lobes of the glabella and the fixed cheeks. 



Fixed cheeks nearly as wide as the anterior portion of the glabella, interrupted 

 by strong, low palpebral ridges that originate at the antero-lateral angles of the 

 glabella and extend obliquely outward and backward to the palpebral lobes; pal- 

 pebral lobes large, about one-half the length of the cephalon, and rising abruptly 

 from the nearly flat fixed cheek; their outer margin is broad, rounded, elevated, 

 semicircular, with a deep groove sloping down to the fixed cheek ; frontal limb very 

 narrow, merely a rounded line between the glabella and the flat frontal rim ; to the 

 sides it merges into the strong palpebral ridge and downward slope of the fixed 

 cheek in front of the ridge ; frontal rim narrow, nearly flat, and rising to the slightly 

 rounded margin. 



Surface apparently smooth, with the exception of a few small, scattered pus- 

 tules on the glabella. 



At this same locality and horizon, and in limestone of the same character but 

 not in the same hand specimen, there are a number of pygidia which appear to pos- 

 sess characteristics distinct from those of any described species and which have been 

 referred to B. alastor. They are transversely semicircular in form, exclusive of 

 the spines on the border. Axis elongate conical, convex, divided by five shallow 

 furrows into five transverse, very slightly convex rings, and a terminal section a 

 little longer than the greatest width of any ring; the terminal section ends some- 

 what abruptly and slopes rapidly downward to the margin ; it is marked at the point 

 where it slopes downward by a small node each side of the center. Dorsal furrow 

 very slight, as the pleural lobes are nearly flat but slightly convex before reaching 

 the margin. 



The pleural lobes are divided by five shallow furrows into five rounded seg- 

 ments and a narrow frontal rim or segment and a posterior, obscure segment ; the 

 furrows and segments, with the exception of the anterior furrow and segment, termi- 

 nate at the inner margin of the border ; the anterior furrow crosses the border, and 

 the anterior segment is continued out across the border, merging into the anterior 

 spine. Border flat, distinctly defined except opposite the anterior segment, and 

 bordered with a series of marginal spines ; these include a long anterior spine, which 

 is a continuation of the anterior margin and a part of the first segment ; back of this 

 there are four pairs of short spines which may be considered in a general way as 

 opposite the four anterior segments; the sixth pair of spines project backward; 

 they are long, broad, flat, and opposite the obscure terminal segment of the pleural 

 lobe; between the two large spines, opposite the dorsal furrow at the side of the 

 axis, are two short spines ; all of the spines are more or less flat and merge directly 

 into the flat border, with the exception of the two anterior, which are connected 

 with the anterior segment and frontal rim. 



The surface of the rings and segments is marked by minute granules; other- 

 wise it appears to be smooth under a strong lens. 



A specimen 7 mm. in length has a width of 12 mm., exclusive of the spines; 

 axis, 3 mm. in width in front, 1.75 mm. at the posterior end; pleural lobe back of 

 the first segment, 3 mm. in width. 



