ORDER IV. 
PHYSOSTOMI, or MALACOPTERI. 
The fishes of this Order are all so-called Malacopterians, that is to say, fishes whose fins are 
composed of soft and articulated rays. They have hut one dorsal fin, properly so called, which 
is nome families, possesses a spine at its anterior margin. Sometimes,also, we observe a fatty 
fold of the skin near the peduncle of the tail—the so-called adipose fin. The ventrals, when 
extant, are abdominal in their positions, and sometimes also provided with a spine upon their 
external margin. The swimming or air bladder has an air duct through, which it communi¬ 
cates with the throat. 
S-zn.—Physostomi, Mull, in Wiegm. Archiv fur Naturg. I, 1845, 131. 
Malacopteri, Owen, Lect. Comp. Anat. Yetebr. 1846, 48. 
There are two tribes, or else sub-orders of Physostomians, representing the abdominal 
Malacopterygians {Malacopterygii abdominales ), and the apod Malacopterygians {Malacopterygii 
apodes) of Cuvier’s classification. 
SUB-ORDER I. 
APODES. 
The ventral fins are wanting. The pectoral fins themselves are not always present. The 
body is elongated, eel-like in its general aspect. The dorsal and anal fins are oftentimes 
continuous with the caudal. 
Syn. — Apodes, Linn. Syst. Nat. ed. XII, 1766.— Owen, Lect. Comp. Anat. Vertebr. 1846, 48.— Bd. Iconogr Encyl. II, 
1850, 203. 
Malacopterygii apodes (in part), Mull, ni Wiegm. Archiv fur Naturg. I, 1543, 328. 
Physostomi apodes s. anguillares, Mull, in W.egm. Archiv fur. Naturg. I, 1845, 131 & 136. 
We are not aware that any apod malacopterians, as understood under this heading, have so 
tar been noticed along the Pacific coast of the United States. They seem to be wanting even 
in the fresh waters of California and Oregon. 
SUB-ORDER II. 
ABDOMINALES. 
The ventral fins are inserted under the abdomen, about midway between the base of the 
pectorals and the origin of the anal; sometimes anteriorly to the middle of that distance, some¬ 
times posteriorly. 
Syn. — Abdominales, Linn. Syst. Nat. ed. XII. 1766.— Owen, Lect. Comp. Anat. Yertebr. 1846, 48.— Bd. Iconogr. 
Encycl. II, 1850, 203. 
Malacopterygii abdominales, Mull, in Wiegm Archiv fur Naturg. I, 1843, 317. 
Physostomi abdominales, Mull, in Weigm. Archiv fur Naturg. I, 1845, 131 & 136. 
