Jordan and ftvcrmann. Fishes of North America. 621 



cleft of mouth moderate ; lower jaw much projecting ; lateral margin of 

 upper jaw formed by the slender, toothless maxillaries. Teeth villiform 

 or almost cardiform on jaws, vomer, and palatines j those on premaxil- 

 laries enlarged. Shoulder girdle free from the skull laterally, the lower 

 branch of the posfctemporal imperfectly ossified. Dorsal short, without 

 spines, inserted before anal ; ventrals abdominal, inserted in front of 

 dorsal, each composed of 3 rays ; base of anal about as long as that of 

 dorsal; caudal fin rounded, with many slender rays; pectoral fin 

 rounded, with a somewhat fleshy base, with 33 to 36 rays, the structure 

 of the base peculiar, the hypefcoracoid and hypocoracoid being undiffer- 

 entiated, represented by a cartilaginous plate, and no actinosts developed. 

 Vertebra) 42. Skeleton everywhere thin and papery. Superior pharyn- 

 geals all separate; first and second without teeth; third and fourth 

 with teeth. Lower pharyngeals separate. Brauchiostegals7or8. Streams 

 of Alaska and Siberia, one species known ; a very singular fish, apparently 

 an ancient type. 



(rtaUii<ln; <iiLL, Smithsonian Report for 1883 (1885), 728.) 



297. DALLIA, Bean. 



Ikdlia, BEAN, Proc. U. S. Nat. Bins., .1879, 358, (pectoralis). 



Characters of the genus included above. (Named for Dr. William 

 Healey Dall, its discoverer, well known as a naturalist and explorer.) 



918. DALLIA PECTORALIS, Bean. 



(ALASKA BLACKFISH ; CHORNIA RYBA.) 



Head 4J ; depth 4 to 4| ; eye small, 6 or 7. D. 12 to 14 ; A. 14 to 16 ; P. 

 33 to 36 ; V. 3; scales 11-77-11 ; B. 7 or 8. Body rather elongate. Pec- 

 toral about half as long as head; ventral i; anal beginning opposite 

 front of dorsal and ending nearly opposite its last ray. Scales on belly 

 very small. Length 8 inches. Streams and ponds of northern Alaska 

 and Siberia; abounding in sphagnum ponds; found in countless num- 

 bers "wherever there is water enough to wet the skin of a fish;" form- 

 ing the chief food of natives. The species feeds on plants and worms. 

 Its vitality is extraordinary. Blackfishes will remain frozen in baskets 

 for weeks and when thawed out are as lively as ever. Turner describes 

 one swallowed frozen by a dog, thawed out by the heat of the stomach, 

 and vomited up alive, (peetoralis, alluding to the broad pectoral fins.) 

 Dallia pectoralis, BEAN, Proc. U. S. Nat. Mus., 1879, 358, St. Michael's, Alaska. (Type, No. 



23498. Coll. L. M. Turner.) JORDAN & GILBERT, Synopsis, 351, 1883; TURNER, Contr. Nat. 



Hist. Alaska, 100, pi. 9, 1886. 

 Umbra delicatissima,* SMITT, 0fver. Kongl. Yeteusk Akad. F<J>rh. Arg. Stockholm, 38, pi. 5, fig. 



1,1881, Pittlekaj, Siberia. 

 Dallia delicatissima, SMITT, in Nordenskjold's Voyage of the Vega, u, 59, with plate, 1881. 



* The following is Dr.'Smitt's original notice of Dallia delicatissima, for which we ar indehted 

 to the kindness of Mr. Barton A. Bean : 



"Hr. Smitt gaf en beskrifning af huudfiskarnes (umbridernas) byggnad och lefnadssatt, med 

 siirskild hiinsyn till en af Vega-expeditioueu fran fiirskvattens-lagunerua vid Pittlekaj hemfiird 

 uy art, Umbra delicatinsiina," 



