S CONTRIBUTIONS TO NORTlS AMERICAN ICHTHYOLOGY - IV. 



>ides of *Jie maxillary rin^ or inner orifice, and have (heir ends turned 

 toward ii : the inferior margin of this oriiiee is armed with a slight ly 



elir\ed denial piece, lia\ ill- live acute points or teeth (the OUttT beili^ 



larger than the three middle): opposite to it on the upper side of the 

 oriiice is another piece having two lar^e, acutely conical teeth, with 

 a smaller central one. The tongue is also clothed with a horny-looking 

 substance, which is ed-ed anteriorly by a ro\v of about twenty liiie 

 teeth. The dorsal lins rise in even curves, which are highest in the 

 middle: the lirst is about one third of its own length from the second. 

 Hack and sides bluish gray, with irregularly scattered yellowish patches; 

 belly yellowish white. Si/.e rather large. (Richardson.) Pacific coast 

 of North America, ascending streams. 



t r<tr<nn//;<>ii indi'iitnlH* GainlinT, Mss.: Kichardsoii. F. B. A. 293: Pctromi/:<i i-ilia- 

 tit* \\\>--, 1'roc. Cal. Ac. Sri. 1-.V1. 11: l'> Inniiii-on ciliatus et licidua Grd. I'm:. R. R. 

 Snrv. '','. ilT'.t: h-hllnjoini^on Iridi ntatuu Gtlir. viii, 5Uti.) 



J{ Lips \\ithuuf IVinjfi-s of papillae. 



5. 1^. 't>ihexolon (Oill) J. &. G. Six-toothed 



This species is said to dill'er i'rom L. tritlcntnta in the absence of a 

 fringe of ])apilla- around the, Imccal disk, and in the presence of six 

 ;ead of lour teeth in the upper transverse row. (tlirard.) Sacra- 

 jneiilo Kiver. 



. / on ir'idniliilnx C,n\. Pac. R. R. Surv. 377; not Rich. : i:,it<>*i>hcin< <i>iltt.rndon 



(iill. Proo. A.-. Nat. Sri. 1'hila. 1MW,:!3.) 



itMainlilnilary plate \\iih six cusps, which arc nearly cnual in size. 



>. I., astori id-.l.) J. &. G. 



Lips fringed; head l\.\ in length; lirst dorsal lower than the second, 

 separated I'rom it by a space nearh eipial to a third of its length; no 

 anal I'm; \ellowish bro\\n, darker above. ((iirartl.) Astoria, Oregon. 

 ( PetromyzonaetoriQixsail, I'ac. K'. K*. Surv. !'>'(!: ZbAt%om^on<u(on'Giinther, viii. .",07.) 



' Ma .,!!:: i s pi ai<- liicus|.iil, i In- small median <-usp wanting; niaiuli I Hilary ]>Iatc \villi 

 . i-hi lath.-i-sinni^, siilicqual li-i-tli. (Lampi Int.) 



7. I.. iliipiiBM':i (Ayres) c.\\\.i.,;id-i;,i,,nd I.<u,ii>ri. 



Lips fiin-ed; head s.] in len-tli; lirst dorsal much lower than the 



lid, and separated from it by a space equal to half of its own length ; 



tail lapei in- to a point ; a single bicuspid tooth on each side of the ori- 



tiec of the mouth. I'acitic coast; a small species, scarcely distinguish- 



able from the Mtiropran /.. tlnri<t/i!is. 



(Petromyton ]iliuul>, .s . \.\n-. . |'i,.,-. c : ,i. ,\c. Nat. Sci. l-.'.-l, 'J 1 ^ : I'ctromyzon ayrcsi 



i' "">: .liiiiii<><;il,.i , il, drill* ( iiraul, I'ac. li. K'. Surv. 3S3.) 



