528 PALAEONTOLOGY OF ILLINOIS. 



inch; length of thorax, 0.33 inch; breadth of do., 0.60 

 inch. 



This species is remarkable for the structure of its eyes, which, instead 

 of being, as usual, covered by the palpebral lobes, have the form and 

 appearance of distinct oval tubercles, with the small, depressed palpe- 

 bral lobes merely connecting with their inner sides. We have not been 

 able to see any traces of facets in the eyes, even by the aid of a good 

 lens, but they doubtless existed beneath the transparent shell covering 

 the eyes. 



We know of no species with which it could be confounded. With the 

 exception of the above mentioned peculiarities of the eyes, it agrees well 

 with the characters of GriffitMdes, and doubtless must be called Grif- 

 Jithides Portlockii, if that group is to be retained as a distinct genus. 



Named in honor of Col. J. E. PORTLOCK, of the Eoyal Ordnance Sur- 

 vey of Ireland, and the author of the genus. 



Locality and position Warsaw, Illinois ; Keokuk Limestone of the 

 Lower Carboniferous series. 



PHILLIPSIA (GKIFFITHIDES) BUFO, M. and "W. 



PL 15, Fig. 10. 

 Phittipsia (Grifflthides) 6/o, MEEK and WOKTHEX, 1870. Proceed. Acad Nat. Sci., Phila., p. 52. 



ENTIRE outline elliptical, the breadth being to the length 

 as 75 to 130. Cephalic shield forming more than a semi- 

 circle, round in front and nearly straight behind; posterior 

 lateral angles terminating in short, abruptly pointed spines 

 extending back to the anterior edge of the thoracic segment. 

 OHabella rather depressed convex, wide anteriorly and nar- 

 rowing posteriorly to the neck furrow, just in front of 

 which, and connected with the palpebral lobes on each 

 side, it has a single small, obscure lateral lobe; neck fur- 

 row broad and well defined, both across the glabella and 

 across the posterior margins of the cheeks; neck segment 

 rather wide, depressed below the level of the highest part 

 of the glabella in front of it. Eyes of moderate size, reni- 

 form, nearly as prominent as the glabella, placed but little 

 in front of the continuation of the neck furrow across the 

 cheeks, apparently smooth, but showing when the outer 



