22 GOBIES OF THE PHILIPPINES 



triangle, and by the flat ventral surface of the head and anterior 

 part of the body. The ventrals are widely separated, and the 

 undersurface of the breast forms a broad, flat, smooth expanse 

 which is used as a sucking disk to attach the fish to rocks. 



The trunk is subcylindrical anteriorly, becoming laterally 

 compressed toward the rear and strongly flattened on the caudal 

 peduncle; the scales are ctenoid and of medium size or larger. 

 The two dorsals are rather far apart. The eyes are of moderate 

 size and directed upward. The small mouth is on the underside 

 of the head behind the pointed snout, with a protractile upper 

 jaw; the preopercle is without spines. There are six branchios- 

 tegals with gill openings of medium width and four gills ; pseu- 

 dobranchiae of medium size are present ; there is no air bladder. 



The Rhyacichthyidae have been grouped by various authors 

 with the gobies, the blennies, and the Callionymidae, or drag- 

 onets, but it is now definitely decided that they belong with 

 the gobies. Long ago Cuvier and Valenciennes saw that their 

 affinities were essentially with the eleotrids, in spite of the 

 fact that the position of their dorsals and ventrals is similar to 

 that in the Platycephalidae and in the European genus formerly 

 known as Aspro. 



Genus 1. RHYACICHTHYS Boulenger 



Rhyacichthys BOULENGER, Ann. & Mag. Nat. Hist. VII 7 (1901) 267. 

 Platyptera (Kuhl and Van Hasselt) CUVIER and VALENCIENNES, Hist. 



Nat. Poiss. 12 (1836) 239 (name preoccupied by Meigen, 1803, for 



a genus of flies). 



In addition to the characters given in the family diagnosis, 

 the genus is further distinguished by the very small teeth and 

 the smooth palate. 



In 1873 Pieter van Bleeker based his Memoire sur la Faune 

 Ichthyologique de China upon a collection of Chinese paintings. 

 In this paper he described twenty-five new species, among them 

 Platyptera sinensis. So far as I am aware, it has not been 

 actually collected, and the characters given in Bleeker's diag- 

 nosis are scarcely sufficient to separate it from Rhyacichthys 

 aspro. 



1. RHYACICHTHYS ASPRO (Kuhl and Van Hasselt) 



PLATE 1, PIG. 1 



Platyptera aspro (Kuhl and Van Hasselt) CUVIER and VALENCIENNES, 

 Hist. Nat. Poiss. 12 (1836) 240, pi. 360; GUNTHER, Cat. Fishes 

 Brit. Mus. 3 (1861) 138; PETERS, Monatsber. Akad. Wiss. Berlin 

 (1868) 268; GUNTHER, Fishe der Siidsee 2 (1876) 191; A. B. MEYER, 

 Ann., Soc. Espana Hist. Nat. 14 (1885) 31. 



