488 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



latter bearing a strong external resemblance to iheEtltcostonutlina; and 

 serving as a connecting' link between them and the more typical forms. 



(PerotdcB part, Giinther, i, 58-78; genera 1'in-it, Lm-iupcrca, Pilcoma, I>ohonoma, 

 rintt, I'lniniiKi, .Ixjiro, Fcrcichthys, and 



' AlKll SpilieS 01IC (II- 1\VO. 



a. PseudobranchisB imperfect or Wanting; preoperole entire; branchiostegals 6. (Ethe- 



b. rremaxillaries protractile. 



c. Body extremely elongate, subcylindrical, translucent, the belly al least naked; 



lateral line complete ; gill-membranes broadly unitrd. 

 d. Anal 'spine single ; anal tin nearly as large as second dorsal. 



AMMOCRYPTA, 252. 

 (Id. Anal spines two ; anal fin small ........... . ..................... IOA, '253. 



cc. Body less elongate. opaque, chiclly scaled. 

 c. Anal spine obscure, normally single. 



/. Lateral line complete, or wanting on a few scales only..BOLEO8OMA, 2.~>4. 

 ff. Lateral line incomplete ......................... . ---- VAILLANTIA, '255. 



ee. Anal spines two, the lirst commonly tbe longer. 



(j. Gill-membranes more or less broadly united; belly with ordinary scales. 

 li. Maxillary bone normal ........................... ULOCKVI i:.\. -,'"!>. 



/</(. Maxillary adnate to the preorbital ................ DIPLKSITM, '257. 



gg. Gill-niembraiifs scarcely connected. 



i. Belly with enlarged caducous plates .......... COTTOGASTI'.I:. 258. 



ii. Belly without enlarged caducous plates .......... IMOSDMA. 'J.V.i. 



lb. Preniaxillaries i\ot protractile. 



j. Lateral line complete. 



k. Ventral line with a series of enlarged, spinous, caducous scales 



or (if these are fallen) a naked strip. 



/. Mouthsmall, inferior, benealha jiig-likesnout .. I'KIU'INA, '-.I'l'i. 

 11. Mouth larger, the snout not projecting beyond it. 



Al.\ lUIDM S. -Jill. 



kk. Ventral line without caducous scales. 

 m. (iill-membranes .scarcely connected. 



n. Anal lin larger than second dorsal H.\I>I:<>PI n:i s, -.' ;-J. 

 ii n. Anal lin smaller I ha n second dorsal . .Norm >N< > I r>. 'Jdii. 

 w//(. (Jill-memliranes liroadly connected .. NANOSTOMA, J(il. 

 jj. Lateral line |)resent, incomplete. 



o. GiU-inemliranes liroadly united ____ KTIII:OM< -MA, -Ji;:.. 



oo. (iill- mcmliranes separate or nearly so. 



l'<: (ii ICIM MV-. -j::i;. 

 jij. Lateral line olisoleto ....................... Min:.>iM:i:cA. -J(i7. 



a. I'seudolirancliia! \\ell di-ve!oped; preoperele serrate; branchiostegals?. ( mind.) 



l>. ( 'aiiine teeth none ; body oblong ....... I'r.KCA. 26H. 



lj>. Canine teeth in ja ws and jialat mi's : body elongale. 



2.12. A^I^IOC'KVE^TA .Ionian. 

 Sand l)in-(cr.\. 



(*/'/ uralijiix Agassi/; not I'l, nn>lci>>* F.gerioii, a ^enns of extinct Canoids.) 

 (.Ionian, Itull. I'. S. Nat. Mils. \. (i. 1-77: type .liiiiimr,-i//>l<i bnini .Jordan.) 



ly slender and elongate, siib-cvlindrieal ; pellucid in life. Head 



'Agaa i/. 1'iull. Mus. Comp. /u.'il. i, :>, i-<;;: type Elheoatoma pclluridum Uainl MSS. 



