122 BULLETIN OF THE LABORATORIES 



furrow, their diameter is about two-thirds of the distance which sepa- 

 rates them, or but slightly less. The groove defining these lobes, the 

 occipital furrow, the groove separating the fixed cheeks and then de- 

 fining the anterior margin of the glabella are all very distinct. The 

 facial sutures begin to define the fixed cheeks at a point near the 

 upper margin of the lateral lobes of the glabella, then they p iss within 

 a moderate distance of the lateral 1 )bes to a place slightly behind the 

 middle of these lobes, after which they turn quite abruptly outward 

 and then curve backward to the posterior maririn of the head. At a 

 point rather beyond the middle of the occipital border of the fixed 

 cheeks, near the edge, there is a low tubercle. On each side of the 

 glabella are two faint groo^'es which are readily overlooked, especially 

 in casts. When examined however with a magnifier, and with the 

 light thrown in the proper direction, they are really quite distinct. 

 The first pair lie about two-thirds the diameter of ihe lateral lobes 

 above their anterior margin; the second pair he about the same dis- 

 tance beyond the second. Being short they are not readily seen in a 

 view from above. The head parts of the Ohio specimens are therefore 

 seen to agree perfectly with those ot the European Sph. minis. The 

 pygidium associated with the Wisconsin species belongs to Ccrauriis 

 Niagarensis, as Hall himself afterwards noted. We fail therefore to 

 discover what the distinguishing features of Sph. Roiningeri are, but 

 Ohio specimens at least belong to Sph. minis. 



UPPER SILURIAN.— AUSTRALLA. 



En-CRINURUS BrOWNINGI, Sp. 71. 



{Plate XIII, Fio. 7.) 



The glabella is very much rounded and inflated for about two- 

 thirds its length anteriorly, the posterior third is much narrower, about 

 half the greatest width of the anterior parts, slightly widening behind, 

 thus giving a marked concave oudine to the sides of the glabella. The 

 occipital furrow is itself not very deep, but the border behind it is ele- 

 vated to such a degree as to give it some importance. Along the pos- 

 terior half of the glabella the tubercles are arranged in quite distinct 

 transverse rows. In the specimen figured, the first three rows have 



