NO. 1549. NEW ORDOVICIAN FOSSILS— WELLER. 563 



MEGALASPIS MINOR, new species. 



Description. — Py gidium small, subelliptical in outline. Axis scarcely 

 elevated above the general surface, about one-third of the total width 

 of the pygidiuni anteriorly, tapering to the rather bluntly rounded 

 posterior extremity, divided by nearh^ obsolete depressions into eight 

 or nine obscure segments. Pleural slopes regularly convex from the 

 sides of the axis to the margins, without a differentiated marginal 

 border, marked by about six narrow, faint, grooved segments which 

 reach halfway across the slopes. Anteriorly, close to the margin and 

 parallel with it a sul>angular groove extends from each side of the axis 

 al)out halfway across the pleural slopes; in front of and outside the 

 lateral extremities of these grooves the surface is abruptly compressed. 



The dimensions of the type specimen are: Approximate length, 

 !J mm. ; width, 14.5 mm. ; width of axis anteriorly, 4.8 mm. ; length of 

 axis, T mm. 



Remarl's. — This species is known only from the pygidium, and even 

 that portion is incomplete. It is referred to the genus Ifegalaspis by 

 reason of the grooved pleural segments. The segmentation is very 

 faint and would probably be even less distinct or perhaps obsolete 

 entirely were the test of the specimen preserved. 



Foi'mation and local ity.-^Ki-sin-Wng limestone, locality 20 B, near 

 Su-kia-pa, province of Ssi-ch\ian. 



ILLiENUS? BRONTEOIDES, new species. 



Description. — Pygidium subsemicircular in outline, flattened on top. 

 Axis ill detined, unsegmented, occup3Mng a little less than one-third the 

 total width of the pygidium anteriorl}^ very slightly elevated in front 

 and merging into the general surface of the pygidium posteriorly. 

 Pleural slopes flattened on each side of the axis, sloping to the mar- 

 gins exteriorly with a slightly concave curve. The .surface of each 

 pleural slope, when the test is removed, is marked by about twelve or 

 thirteen very narrow and scarcely elevated ribs, which are grooved 

 longitudinally and extend from the indefinite axial furrows about to 

 the line where the surface begins its more abrupt slope to the lateral 

 margins. 



The dimensions of the type-specimen are: Length, 8.5 mm^; width, 

 14.8 mm.; width of axis anteriorly, 4.5 mm. 



ReinarJiS. — This species is represented bv a single specimen in the 

 collection, a nearly complete pygidiiau. It is a peculiar form, having 

 the general contour of an lUxnus, but with the pleural slopes faintly 

 segmented, suggesting the genus Bronteus. These segments are YQvy 

 faint, however, and would possibly not be visible at all were the 

 specimens completely covered with the test. 



Formation and locality. — Ki-sin-ling limestone, locality 20 C, near 

 Su-kia-pa, province of Ssi-ch'uan. 



