586 



PISCES. 



[ACA. — ACO. 



Family IcnTHYODORULiTES. — Acondylacanthus, Amacanthus, Anaclitacan- 

 thus, Asteroptychius, Batacanthus, Bythiacanthus, Compsacanthus, Ctena- 

 canthus, Cyrtacanthus, Drepanacanthus, Edestus, Erismacanthus, Euue- 

 macanthus, Gam psacaa thus, Gisacanthus, Glymmatacanthus, Gyracauthus, 

 Homacanthus, Lecracanthus, Listracanthus, Machseracanthus, Marracan- 

 thus, Oracanthus, Orthacanthus, Physonemus, Puigeacanthu3, Stenacan- 

 thus, Xystracanthus. 



Order Raiina. 

 Family Psammodontidje. — Copodus, Psammodus. 



Acanthaspis, Newberrv, 

 vol. 2, p. 36. [Eiy 

 aspis, shield.] 



1875, Obio Pal., 



akiuitha, spine; 



Cranium plates some- 



what quadrangular at 



one etui, then abruptly 



bending to one side, 



and prolonged to an 



acute point; surface 



carinated and tuber- 



culated. Type A. ar- 



mata. 

 armata, Newberry, 1875, 



Ohio Pal., vol. 2, p. 37, 



Up. Held. Gr. 

 Acantiiodes, Agats ; z, 1833, 



liecherches bur les 



Poiss. Fob*., vol. l,.p. 



19. [Ely. a k ant ha, 



spine.] Fish lepidoid, 



mouth wide; lower 



j iw longer than the 



ui>per; teeth brush- 

 like; scales small; dor- 

 sal li n 

 opposite 

 anal; 



pectoral Fro. 1007.— Acantlin 

 la r v f> • * ,, "- t « '»f»irl"K *pi 

 i a gc, side of cranium, 

 first ray 



of eacli fin strong, large, 

 stiff; ravs of caudal fin 

 close. Type A. bron-d. 

 affinis, Whiteaves, 1889, 

 Tiaus. li»y. Soc. Can., 

 vol. 6, p. 77, Low. Devo- 

 nian. 

 concinnns, "Whiteaves, 

 1889, Trans. R >v. Soc. 

 Can., vol. 6, p. 77, Low. 

 Devonian. 



probably * in AcA ntiiolepis, Ne w b e r r y , 

 their relative 1875, Ohio Pal., vol. 2. 



povidone. p> 38< [E fy . abintha, 



spine ; lepin, scale.] Tuberculated cran- 

 ial or dermal plates, having a prevailing 



Fin. 1098— Acan- 

 iiiolepis pus- 

 tulosas. Be- 

 duced outlines 



spatulate outline; some are thin and 

 have the appeaiance of large, elon- 

 gated, unsyniuK tiical scales; others are 

 stronger and produced into joints that 

 sotneiiints become spines. Tjpe A. 

 j uist ulut a. 

 pus.ulosa, Newberry, 1875, Ohio Pal., 

 vol. 2, p. 38, Up Held. (Jr. 

 Acondyi. acanthus, St. John & 

 Worthen, 1875, Geo. Sur. 

 Hi., vol. 6, p. 432. [Ety. 

 ahmdybis, without bony 

 knobs; akanthn, spine.] Fin 

 rays lontr, gradually taper- 

 ing, laterally compresst d, 

 moderately curved posteri- 

 orly; lateral faces longitudi- 

 nally fluted; coatee smooth, 

 enamehd, increasing by bi- 

 furcation and implantation ; 

 posterior face excavated 

 longitudinally, without me- 

 dian keel; posterolateral 

 angles bear- 

 ing a row of f\ 

 d o w nwn rd '; \ 

 hooked den- \\\ 

 tichs; pulp 

 cavity occu- 

 pying the 

 posterior half 

 of the spine. 

 Type A. gra- 

 cilis, 

 ceq uico«tatus, 

 St. John & 

 Worth en, 

 18 75, Geo. 

 Bar. 111., vol. 6, p. 434, 

 Keokuk Gr. 

 gracilis, St. John & Wor- 

 then, 1875, Geo. Sur. 

 Ill , vol. 6, p. 433, Wa- 

 vei ly or Kinderhook Gr. 

 mudtfianua, St. John & 

 Worthen, 18S3,Geo. Sur. 

 III., vol. 7, p. 244, Up. 

 Coal Meas. 

 nuperus, .St. John & Wor- 

 then, 18*3, Geo. Sur. 

 Ill, vol. 7, p. 242, Up. 

 Coal Meas. 

 occidentalis, Newberry 



aspis Hrmata. 

 ne from left 



Fig. 1009.— Aeon- 

 Uyliicu ii i li u s 

 gracilis. Side 

 view of spine 

 mng. y t diam- 

 eter. 



& Worthen, 



1860, (Leptacanthus occidentalis.) 



