350 TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



gadoids and ophidiids shows a certain conformity of structure, through which these fishes 

 seem to constitute a group with depressed skulls, in contrast with the compressed skulls of 

 the greater number of acanthopterygians. Starks (1911i, pp. 747-748) suggested that the 

 gobioids may be an offshoot of the scorpsenoids; but Regan (1911c, p. 731) is unable to accept 

 this suggestion and refers the gobies to the Percomorphi, defining for them the suborder 

 Gobioidea. 



In a valuable study of the skull of Mistichthys (Fig. 230) the smallest known fish, Miss 

 Lois Te Winkel, who has courteously given me permission to reproduce the accompanying 

 figure, finds that the skull retains many features that are usually found in young stages 

 of teleosts. 



The otoliths of the Gobioidea, as described by Frost (1929a, pp. 126-129), are highly 

 specialized; more or less oblong with an enclosed ovate or biovate sulcus and other peculiari- 

 ties. This "Gobiid" form is "unique and unmistakable, and has persisted since Eocene 

 times, large numbers occurring in the Barton Clay of Hampshire, which closely resemble the 

 otoliths of recent fishes" (p. 126). Starks (1930, pp. 218, 219) gives abundant data for the 

 present conclusion that the details of the scapula, coracoid and actinosts in the gobies, go 

 to make up a distinctive gobioid type, which is convergent in some features toward the 

 cottoid type but must have been derived independently from a more primitive percoid 

 girdle. We seem therefore to be compelled to regard the gobioids as one of the early off- 

 shoots of the primitive percoid group. 



Symbranchii 



In the fresh and brackish waters of India and Burma occurs a greatly elongate eel-like 

 fish, the Amphipnous cuchia, which, according to Tate Regan (1929, p. 327), "spends the 

 greater part of its life out of the water, wriggling along the banks, in which it burrows during 

 the dry season. It visits the water in search of food, worms, crustaceans and small mol- 

 luscs." Boulenger (1910, p. 599) says that "this amphibious fish, when in the water, 

 constantly rises to the surface for the purpose of respiration, and it is often found lying in 

 the grassy sides of ponds after the manner of snakes." Thus it is one of several fishes of 

 different orders which have been able to come up out of the water or burrow in the mud by 

 virtue of possessing a respiratory air-sac of some sort. Regan (1929, p. 327) states that in 

 the cuchia, the air-breathing sacs are a pair of "diverticula of the pharynx which lie on each 

 side of the back-bone above the gills. . . ." According to Boulenger (1910, p. 598), 

 "Of the three branchial arches the second alone possesses gill-filaments; the third supports, 

 in their place, a thick and semi-transparent tissue; the principal organs of respiration are 

 two small bladders, resembling the posterior portions of the lungs of snakes, which the 

 animal has the power of filling with air immediately derived from the atmosphere. . . ." 



The skull of Amphipnous is stated by Tate Regan (1912^, p. 390) to differ from that of 

 the Symbranchidse (see below) only in features which are connected with the presence 

 of these respiratory sacs; these have pushed away the pectoral arch from the skull, so that 

 the posttemporal is reduced or absent ... on the outside the sacs are covered by the 

 operculum and suboperculum, "which are enlarged and form thin, almost membranous 

 laminae," (1929, p. 327). 



In the fresh or brackish waters of Central and South America, West Africa, India, 

 Southeastern and New Guinea, are found the representatives of the family Symbranchids, 

 with one marine form (Macrotrema), from Penang and Singapore (Tate Regan, 1929, p. 327). 



