1880.] NATURAL SCIENCES OF PHILADELPHIA. 17t 



head. The frontal limb is triangnlar in outline, and prolonged 

 into a prominent projection, the bourrelet of the limb is defined 

 by a triangular ridge which forms the base of the projection. 

 The projection is formed by the thickening of the crust and by 

 the union of the outer marginal borders along the median line, it 

 is pointed and has its sides deflected. The space between the front 

 of the glabella and the base of the projection is somewhat de- 

 pressed. 



The p3'gidium is obtusel}" triangular, with the front greatly 

 arched in uncrushed specimens, but this character seems to be 

 confined to the medium-sized specimens ; the larger forms are not 

 so much arched, and correspond in this respect to typical pygidia 

 of G. hlumenbachii. The axis occupies along the anterior border 

 about one-third of the width of the tail, and gradually tapers 

 posteriorly into an obtuse point ; it is marked with about eight or 

 nine articulations, the anterior one being slightly arched forwards, 

 but the others are extended almost straight rig. 2. 



across it. The dorsal furrows are well defined. 

 The lateral lobes are marked with five pairs of 

 ribs, four of which are grooved and double half- 

 way up ; they are contracted along the dorsal 

 furrows, but widen out laterally. The ribs curve caiymene rostrata 



" Vogdes. The pygi- 



downwards and backwards, and are separated dium usually found 



associated with the 



from each other by well-defined grooves, the head. 



last pair unite and form a ridge extending around the posterior 



termination of the axis. 



Geological Position. — Clinton Group, Taylor's Ridge, near 

 Catoosa Station ; and also at Dug Gap, Georgia. 



Among the trilobite specimens wbicli I have collected in 

 Georgia, there are three movable cheeks and one pygidium 

 showing a strong resemblance to the same parts of Galymene 

 Glintoni as figured by Prof. Hall in Pal. N. Y., vol. ii, pi. 6(1 a, 

 fig. 5. These fragments were found associated with two glabella, 

 having characteristics not shown by the illustrations of the species 

 just referred to; therefore, for the purpose of comparison, I 

 carried the specimens to the American Museum, and through the 

 courtesy of Prof. Whitfield was enabled to study the trilobites 

 found in the Clinton Group of New York. The Georgia forms 

 are almost identical with those of New York, but show some 



