604 



SILURIAN TRILOBITES, 



type of D. caudatus (Briinnich) Emmrich, and D. I/ausmaniii, 

 Brongniart." 



Under these circumstances, the adoption of Hausmannia in 

 place of Dalmanites will surmount all difficulties in connection 

 with the latter name. This suggestion is strengthened by the 

 fact that Barrande's Dalmanites, as pointed out by Schmidt, 

 included Trilobites not only of the type of Asaphus caudatus, but 

 also all other Phacopidse which did not agree with Fhacojjs as 

 restricted by him, and are comprised b}^ other writers in Acaste 

 and Chasmojys. 



Hausmannia meridianus, sjy.nov. 



(PL XXXVIII., figs. 1-8; PI. xl., fig. 1.) 



Phacops ( Odontochile) caudatus, McCoy {non Briinnich), Prod. 

 Pal. Vict. Dec. iii. 1876, p. 13, t. 22, f. 1-7; t. 23, f. 7-10. 

 Sjy. Char. — Body. — Oblong ovoid. Head-shield or cephalon. — 

 Semicircular, finely granulated, moderately inflated, surrounded by 

 a thickened limb marked off from the cheeks and glabella by a 

 fairly conspicuous groove. Glabella large, subpyriform, with 

 straight and oblique sides, separated from the cheeks by deep and 

 wide axial furrows; frontal lobes very tumose, and together sub- 

 elliptical in shape, and in some specimens overhanging the 

 furrows very slightly; the remaining lobes are flat and small, second 

 pair subtriangular, third and jDosterior pair oblong; frontal 

 furrows wide, and moderately deep, joining the axial furrows 

 just in front of the eye, crossing the glabella very obliquely 

 and almost meeting, the basal and median pairs linear, deep, 

 and slit-like (in casts), and not reaching the axial furrows; 

 posterior corners of basal lobes sloping rapidly into the 

 axial furrows; fixed cheeks small, genal lobe* inflated, sloping 

 rapidly into the axial furrow, separated from the palpebral lobe 

 by a distinct groove, which anteriorly passes into the axial groove, 

 and posteriorly passes round and under the eye; free cheeks large, 



* That portion of the fixed cheek between the palpebral lobe and t 

 axial furrow. 



