OKDKU III 



PROPAKIA 



030 





132-J. 



Ckitrut li'-yr. 



(Et. E); Kozolu]., 

 (after Barramlf). 



Silurian 



eleven segments, u,,t distinctly marked ,,||- from the thorax. 



Kurope and North 



America : also I )e 



vonian of North 



America. 



H o m a I on <>f n .-, 

 Koenig (Fig. I:',- 1 . 

 Body usually large, 

 elongate, narrowing 

 In-hind, indistinctly 

 trilobed ; gbihclla 

 smooth, flattened and 

 almost quadrate : 

 liygidium elongate 

 triangular, posterior 

 margin rounded or 

 pointed, axis with 

 ten to fourteen annu- 

 lations, sometimes 

 smooth and without 

 apparent segments. 

 Ordovician to De- 

 vonian ; Europe, 

 America, and South 

 Africa. 



Family 3. Cheiru- 

 ridae. Salter. 



Glabella well de- 

 fined. Free cheeks 

 small, sometimes much 

 reduced. Sutures 



extending from in front of ///- ,/, ,// ,/,//,,. inward to > >h< n 



obliquely forward, cutting the <ini<-riar //'/<///> /// front n,l on each 

 side of the glabella. Eyes n*nUii s///////. Tliorx., <;/"/'//.< 

 eighteen seijnnn/.-; <i< nerally eleven ; pi n r <;/>-// .<////// into 

 spines. Pygidiwn *//;<>//, /'//// from ////-- to five teg$ 

 elements commonly proJnrnl info .-/<//">. Principally Ordovician 

 and Silurian, l>ut extending into the Devonian. 



Cheirnni.^ T-eyr. (Figs. 1 317, E, 1322). Glabella strongly convex 

 and deeply grooved by three ]aiis of lateral furrow-; thoracic 

 segments eleven, WO raivly nine to thirteen : pygidium with well- 

 marked axis of lour simulations, the pleura ju-oloiigcd into points 

 or spines. Species grouped into a number of -ub-gt-m-ra. Ordo- 

 vician and Silurian : Kuiope and North America. 



Amphion, Pander (Fig. 1323). CVphalon broad and short, 

 with a distinct rim around the margin ; ghd>ella not .-trough 

 elevated, marked by two pairs of >id- furrow- and >hrt frontal 

 furrow.-. r rhoraeic segments fifteen to eighteen with inflated 

 Silurian; pleura; pygidium smaller than cephaloii, pleural rib- extended 

 into spines. Commonly found in the enrolled condition. Ordo- 

 vician ; Europe and North America. 

 Sphaerexochus, Beyr. (Fig. 1324). (Ilabella ovoid or globular, with three paire of 



Fin. 1321. 



dn-.'ii. Silurian 



lit J/jii i,n- 

 Lockport, 



Kich\v. 

 Russia. 



Ki... 

 of .( 

 Onluvician : I'ulkuwa, 



FIG. 1324. 



'uis minis, 



Beyr. 



Listice, Bohemia. 



(after Barrancle). 



