250 Epwın CHAPIn STARKS, 
the genus Umbra, the sole representive of the family Umbridae, a 
member of the order Haplomi. He expressed his doubt as to the 
pertinence of so associating it by placing a question mark after 
Umbridae. From external characters Dr. Bean was justified in con- 
sidering it under this family. It resembles Umbra in having the 
dorsal and anal fins short, rounded, and posteriorly placed; the 
caudal fin broad and rounded; the small ventrals close in front of 
the anal; the caudal peduncle deep and compressed; small teeth in 
bands on jaws, vomer and palatines; cycloid scales on head and 
body; and in having similar habits of living in the mud and among 
the weeds of sluggish streams and ponds. 
In the year 1885 Dr. THEopDorE GiLL !) in studying the skeleton 
discovered certain peculiarities of the shoulder girdle, and created 
for it the order Xenomi, which he thus defined: “Teleosts with the 
scapular arch free from the cranium laterally, and only abutting on 
it behind, coracoids represented by a simple cartilaginous plate without 
developed actinosts, and with the intermaxillary and supramaxillary 
bones coalescent.” 
In 1893 Dr. C. H. GILBErRT?) found the character of the maxil- 
laries and the posttemporal to be untenable (as quoted in this paper 
under the descriptions of those elements) thus leaving the order 
resting on the sole character of the shoulder girdle. 
My object in undertaking this investigation of Dallia was to 
further study its remarkable shoulder girdle, and attempt to work 
out its entire osteology. Primarily, however, I was influenced in 
this direction by Dr. ©. H. GILBERT who placed in my hands some 
particularly well preserved specimens, which he had collected in 
the swampy tundra near the mouth of the Nushagak River, Alaska, 
in the summer of 1903. Much of my success in working out the 
delicate shoulder girdle cartilages I attribute to this excelent material. 
Osteology. 
Craniüm: 
Most of the bones of the cranium are rather widely separated 
by cartilage, especially those of the posterior and lower surfaces. 
1) In: Jorpan’s Catalog. of Fishes of N. A. U. S. Fish Comm. 
1885, p. 839. 
2) In: Rep. U. S. Fish Comm. 1893, p. 403. 
