2250 Bulletin //, United States National Museum. 



less ciliated. Eyes small, almost superior. Gape wide, the maxillary in 

 the adult inordinately developed, prolonged backward to the base of the 

 pectorals, its posterior part a cartilaginous expansion, connected to an 

 expansion of the skin of the lower jaw, thus forming a channel backward 

 from the mouth, almost exactly as in NeocUnus and Opisthognathus, 

 genera otherwise very different. Teeth small, even, in broad bands. 

 Skull in adult with a strong median keel, not abruptly widened behind 

 the eye, triangular behind; young with the keel obsolete. Dorsal lius 2, 

 the second high, the first of 6 very weak spines, none of which is 

 exserted- soft dorsal and anal short; caudal less rounded; pectorals 

 large ; isthmus broad. Singular little fishes, in brackish waters, burrow- 

 ing in the mud ; confined to the Pacific. (Named for Theodore Gill.) 



a. Head moderately depressed ; dorsal fins close together. mirabilis, 2582. 



aa. Head very broad and depressed; distance between dorsals i length of first dorsal. 



DETRUSUS, 2583. 



25S2. GILLICIITHYS 3II1UBILIS, Cooper. 

 (Long-jawed Goby.) 



Head 3i; depth 5; eye 6 to 7; snout longer than eye, low, little 

 decurved. D. VI-12; A. 10; vertebra3 15+17. Body stout, somewhat com- 

 pressed behind, broad and depressed anteriorly ; head broader than deep, 

 its width li, its depth 2 or more in its length; interorbital space greater 

 than eye. Mouth very large; maxillary variable, extending to base of 

 pectoral in adult, broadened behind; fold of lower lip extending its full 

 length. Teeth all alike, small, fixed, and in bands, the band of the lower 

 jaw broader than that of the upper. Scales small, cycloid, irregularly 

 placed, largest from front of dorsal backward, decreasing in size ante- 

 riorly; head, Itreast, belly, and i of nape naked. Dorsal spines not 

 filamentous, not as long as the soft rays which are little more than i 

 depth of body; caudal broad, short, rounded; pectorals broad and 

 rounded, longer than veutrals, 2 in head. Skull not abruptly widened 

 behind eye, as iu (lohins, being triangular posteriorly. No lateral ridges; 

 a strong median keel; a short transverse crest behind orbit. Interorbital 

 not deeply grooved, with a blunt median ridge. Orbit not bordered by 

 anj' prominent ridges. Teeth iu both jaws, close set, in bands, all alike. 

 Dull olive, very finely marbled with darker; sides of head and maxillary 

 finely punctuate; fins olive; belly yellowish. Length 8 inches. Pacific 

 coast of North America, from San Francisco to Cerros Island ; a most 

 remarkable little fish; very abundant in the mud ilats in shallow water 

 along the California coast, bui'rowing in holes in the mud like a crawfish, 

 and readily taking the hook baited with flesh or worm when dropped 

 into the mouth of the burrow, {mirabilis, wonderful.) 



GilHchthys mirabilU, Cooper, Proc. Cal. Ac. Sci. 1863, 109, San Diego Bay ; Lockington, 

 Amer. Nat. 1879; Jordan & Gilbert, Synop.sis, 63C, 1883 ; Jordan & Eigenmann, i. c, 

 510; Evermann & Jenkins, Proc. V. S. Nat. Mus. 1891, 162. 



Gobius townsendi, EiGENMANN & Eigenmann, Proc. U. S. Nat. Mus. 1888,463, San Diego; 

 young. 



