BY R. ETIIERIDGE, JUNR., AND JOHN MITCHELL. 721 



Fig. 12. — Another and less perfect specimen; slightly enlarged. Coll. MitcheU. 

 Fig. 13. — A third example; slightly enlarged. Coll. Mitchell. 



Plate Liv. 



Ceratocephala longispina, Mitchell, sp. 



Fig. 1. — Portion of thecephalonand tliorax; slightly reduced. Coll. Mitchell. 



Fig. 2. — Cephalon less the free cheeks, witli the occipital spines in situ, 

 the left one showing a tendency to curl under as in the genus 

 Selenopeltis; somewhat enlarged. Coll. Mitchell. 



Fig. 3. — A similar specimen; somewhat enlarged. Coll. Mitchell. 



Fig. 4. — Free cheek, with the eye in 'situ; somewhat enlarged. Coll. 

 Mitchell. 



Fig. 5. — Distal end of one of tlie posterior thoracic pleurae with its enor- 

 mously elongated spine; somewhat enlarged. Coll. Mitchell. 



Fig. 6. — Crushed cephalon and thorax, with the position of the occipital 

 spines indicated; somewhat enlarged. Coll. Geol. S^irvey 

 Queeiflancl, Brisbane. 



Plate LV. 



Structural diagrams of the cephalon of Odontophura and of Ceratocepthala. 

 Fig. \. — Odontojjlf'ura. 

 Fig. 2. — Ceratocephala. 



Reference Letters. 



aa. Central lobe of tlie glabella, hh. Anterior lateral lobes of the glabella 

 (seldom present), cc. Median lateral lobes of the glabella, dd. Basal or 

 third pair of lateral glabella lobes, ee. Lateral lobes of the neck ring. Jf, 

 Genal or cheek lobes (in Odontopdeura mostly very rudimentary), gg, 

 Genal spines. hh. Neck furrow, iiii. False furrows, jj. Front lateral 

 expansions of the central lobe of the glabella, kh. Lateral cheek furrows. 

 mm. Cheek borders with spines, no. Ocular ridge. o)i. Posterior extension 

 of ocular ridge present in some Ceratocephcda. oo. Eyes, j)- Palpebral 

 lobes, very small in Odontoj)lei(ra. q. Genal spine ridges, r. Neck ring. 

 zz. Occipital spines. tt. Palpebral furrow. xxxxx. Axial furrows, yy. 

 Lateral extensions of the neck furrow, vnv. Genal lobe ridges, joining the 

 genal lobes to the lateral lobes of the neck rings and interrupting the 

 lateral extensions of the neck furrow, fs-fs. Front border of the glabella, 

 sometimes l)i!aring fine spines, fs.o.fs. Facial sutures, sometimes not 

 defined or soldered as in the case of C. Vogdesi, nobis, ix.ix.ix.ix. Lateral 

 glabella furrows, seldom more than two pairs present, tri. Triangular 

 areas, very small or absent from Ceratocephala. hv. Branches of the neck 

 furrow or continuations of the false furrows, tn. Central tubercle of the 

 neck ring. fs.x. Thickened borders or ridges of lateral extensions of the 

 fixed cheeks. 



