XXIII 



ACANTHOrTERYGII 



711 



5 genera : Batrachus, Opsanus, Thalassopliryne, Thalassothia, and 

 Poriclithys. The eggs of Batrachus tan are very large, inch 

 in diameter, and are deposited in a little retreat provided by the 

 parent ; the male assumes the care of the brood ; the young fasten 

 themselves to rocks by means of an adhesive ventral disk, which 

 soon disappears. 1 



In Thalassophryne, from the coasts of Central America, the 

 opercular spine and the two dorsal spines are perforated, and 

 convey poison from subcutaneous sacs situated at their base. 2 

 In the American genus Porichtliys the head and body bear series 

 of greatly developed mucous pores, some of which simulate 

 the photophores of Scopelus, but are not luminous. 3 



FIG. 429. Porichthys porosissimus. (After Goode and Bean.) \ nat. size. 



Fam. 11. Pholididae. Suborbitals not forming a subocular 

 shelf; mouth scarcely protractile, with thick lips. Praecaudal 

 vertebrae similar to the caudals, without transverse processes, 

 with htemal arches ; ribs sessile. Gill-membranes free from the 

 isthmus ; 4 or 5 branchiostegal rays ; gills 4, a slit behind the 

 fourth ; pseudobranchiae present. Scapular arch as in Blenniidae. 

 Ventral fins jugular and rudimentary, or absent. Body elongate, 

 compressed, with very small scales. Dorsal and anal fins 

 elongate, the former constituted entirely of non-articulated rays 

 or spines. Caudal fin distinct, with expanded hypural. 



Small shore fishes of the Northern Seas, differing from the 

 Blenniidae in the structure of the praecaudal vertebrae, in spite 

 of the external resemblance which the two known genera, Pholis 

 (Centronotus) and Apodiclithys, bears to Anoplarchus and Xiphistes. 

 Species about 10. 



1 On the breeding habits and development of this fish, cf. J. A. Ryder, Bull. 

 U.S. Fish Comm. vi. 1886, p. 4, and Proc. Acad. Philad. 1890, p. 407. 



2 Cf. Giinther, Trans. Zool. Soc. vi. 1869, p. 437. 



3 Cf. C. W. Greene, Journ. of Morphol. xv. 1899, p. 667. 



