Jordan and Evermann. — Fishes of North America. 785 



upper most distinct; back with a series of similar spots, one conspicuous 

 at beginning and another at end of first dorsal; dorsal mottled ; caudal 

 barred; head smutty ; .1 blue-black spot on middle of opercle ; a narrow, 

 silvery lateral band ; young translucent, with dark spots. Length 3 to 4 

 inches. Sandy or Aveedy lagoons along the Columbia Kiver, locally abun- 

 dant at the mouth of theUmatillaaud Wallula rivers ; our specimens taken 

 by Thoburn and Rutter in the Wallula at Walla Walla, (trantimoiiianua, 

 beyond the mountains.) 



Columbia Iransmoniaiia , Eigenmann it Eigenmann, Science, Oct. 21, 1892, 2:^3, mouth of Uma- 

 tilla River, Oregon; (Coll. Eigenmann); Gilbert & Evermann, Investigations in the 

 Columbia Kiver Basin, 51, 1894. 



Suborder XENARCHI. 



We place in a distinct sul)order, next to the Sahnoiifrcd', the singular 

 little family of the Pirate Perches, which finds its natural position between 

 the Percojysida' and the Percoid forms. Structure of mouth and skeleton 

 so far as known essentially that of the Percoid fishes. Dorsal fin single, 

 with few small spines ; ventrals thoracic, with a small spine, and more 

 than five soft rays. Air duct not examined, probably obsolete, the air 

 bladder large and adherent. Intestinal canal ending at the throat in the 

 adult, the vent variously posterior in the young. Vertebrje 29. One 

 family among existing forms. Several fossil genera. {Erismatopterus, 

 Amphiplaga, etc.) seem to stand between Aphredoderus and Elassoma, 

 which seem to be near relatives on the one hand, as Percojisis is on the 

 other, (ffjof, strange ; apxdg, anus.) 



Family CV. APHREDODERID^. 



(The Pirate Perches.) 



Body oblong, elevated at the base of the dorsal, compressed behind, the 

 head thick and depressed, the profile concave. Caudal peduncle thick. 

 Mouth moderate, somewhat oblique, the lower jaw projecting; maxillary 

 reaching to anterior border of the eye. Teeth in villiform bands on jaws, 

 vomer, palatines, and pterygoids. Premaxillariesnot protractile; maxil- 

 laries small, without evident supplemental bone. Preopercle and pre- 

 orbital with their free edges sharply serrate ; opercle with a spine. Bones 

 of skull somewhat cavernous. Sides of the head scaly. Lower pharyn- 

 geals narrow, separate, with villiform teeth. Gill membranes slightly 

 joined to the isthmus anteriorly. Gill rakers tubercle-like, dentate. 

 Pseu do branchiae obsolete. Gills 4, a small slit behind the fourth- 

 Branchiostegals6. Scales moderate, strongly ctenoid, adherent. Lateral 

 line imperfect or wanting. Vent always anterior, its position varying 

 with age,* from just behind the ventral fins in the young, to below the pre- 

 opercle in the adult. Dorsal fin single, median, high, with but 3 or 4 



* This singular fact was first noticed by Prof. Stephen A. Forbes. 

 F. N. A, 51 



