Carboniforoiis Trilohiles. 93 



with about 14 segments each, the very short posterior ones being nearly in 

 line with the axial lobe, while the others grow gradually more transverse 

 anter{orl3^ so as to show only a moderate obliquity towards the front ; all 

 extending down so as to leiive only a very narrow, undefined, smooth mar- 

 ginal space, and each ornamented by from 3 or 8 to about 12 tubercles, the 

 number increasing regularly, with the length of the segments, towards the 

 anterior. Surface between the segments and tubercles smooth. Lenglh of 

 pygidium, 0.95 inch ; breadth, 1.45 inch ; convexit3^ 0.40 inch. * * * '» 

 Locality and iiodtlo It. — Kinderhook, Pike Co., 111. Burlington division 

 of the Lower Carboniferous. 



CJRIFFITHIDES, Portlock, 1843. 



Plate III. Figs. 3, 5, 6 & 13. 



Griffithides, Portlock, 1843, Geol. Rep. Londonderry, p. 310. 



Description. — Outline oblong-oval, glabella pyriform, gibbous in front, 

 destitute of lateral furrows ; basal lobes inflated. Occipital lobe broad, eyes 

 small, lunate, smooth ; facial suture marking divisions of the movable 

 cheek clearly defined, outline broadly triangular, outer posterior angles 

 sometimes produced into a cheek-spine. Thorax with 9 segments. Pygi- 

 dium rounded, composed of about 13 coalesced axial rings. Hypostome : 

 the anterior border is strongly arched, the central body is tumid ; the two 

 alae form blunt angles, giving breadth to the attached anterior border ; the 

 sides curve inward almost to the lower end, where there is a slight expansion ; 

 the lower free extremity is only half as wide as the upper. The border is 

 raised and the angles truncated, the inner portion of the lower extremity is 

 slightly raised {G. gloUceps). 



GRIFFITHIDES PORTLOCKII, Meek and Worthen. 



Plate III, Fig. 9. 

 PhilUpsia (Griffithides) Po7'tlockli, Meek and Worthen, 1865; Proc. Acad. 



Nat. Sci. Phila., p. 268. 

 PhilUpsia (Griffithides) Portlockii, Meek and Worthen, 1873 ; Geol. and 



Palseont. Illinois, Vol. V, p. 525, pi. 19, fig. 6. 

 Griffithides Portlockii, Vogdes, 1886 ; Bibliography Palajozoic Crustacea. 



The authors give the following description of this species in their final 

 report : 



"Entire outline subovate. Cephalic shield sub-semicircular, nearly twice 

 as wide as long, moderately convex, rounded in front and straight behind, 

 with posterior lateral angles terminating in short, pointed spine-like append- 

 ages extending back to the third thoracic segment. Glabella ovate, tumid, 

 contracted and depressed behind, widest and most convex or ventricose an- 

 teriorly, where it is about one-third narrower than its length from the neck- 

 segment to its rounded front, which is not margined by a projecting rim ; 

 very distinct from the cheeks in consequence of its greater convexity ; pos- 



