138 PROCEEDINGS OF THE NATIONAL MUSEUM vol.84 



a*. ToxactiJiium absent ; pulviimlus if present small and not shield- 

 or disk-shaped, 

 c*. First dorsal fin represented by at least one ray; nape and 

 opercies scaleless. 

 d^ One long etenactiniura present. 



e\ Ctenactinium thin and considerably curved, without a 

 membranous fold along its edge ; priapium, in region of 

 infrasulcar prominence, lacking a flat, many-spiued 

 process; posterior border of priapium with a series of 



soft, comblike projections Neostethus Regan 



e^ Ctenactinium not greatly curved, with a broad membran- 

 ous margin along lower side of its proximal half; re- 

 gion of infrasulcar prominence with a large, flat, fleshy 

 process armed on its upper and posterior border with 

 9 or 10 short, sharp, recurved spines and on its anterior 

 border with 2 longer spines directed forward ; posterior 

 end of priapium without comblike appendages_Plectrostethus Myers 

 d'. Two long ctenactinia present; no comblike appendages at 

 end of priapium. 

 f. Pulvinulus plainly evident externally as an oval promi- 

 nence with a depressed center, on aproctal side of 

 priapium ; body extremely slender and elongate ; brack- 

 ish-water fi.shes Ceratostethus, new genus 



f. Pulvinulus not evident externally; body moderately 



heavy ; hill-stream fishes Gulaphallus Herre 



(f. First dorsal fin absent; 2 ctenactinia, the lesser one very 



short; nape and opercies scaly Mirophallus Herre 



Genus PHALLOSTETHUS Regan 



PHALLOSTETHUS DUNCKERI Regan 



No further specimens of this species, which was described from 

 Johore, have been reported since Kegan's original description. 



Genus PHENACOSTETHUS Myers 



PHENACOSTETHUS SMITHI Myers 



Neostethus lankesteri (not of Regan) H. M. Smith, 1927, p. 353 (Bangkok, 



Siam) ; 1929, p. 13 (Bangkok, Siam). 

 PJienacostcthus smithi Myers, 1928, p. 6 (Bangkok, Siam).— Bailet, 1936 

 (anatomy). 

 This minute species is represented by several hundred specimens 

 in the collections of the United States National ISIuseum (nos. 88659, 

 88667, 93506, 93507, 93508) , as well as paratypes of the species (nos. 

 92297, 92979). All were collected in canals in the city of Bangkok, 

 Siam, by Dr. Hugh M. Smith. This is the only phallostethid present 

 in Dr. Smith's Bangkok collections, and there is no doubt that it is 

 the species he reported in 1927 as Neostethus J^nkesfeH. P. smithi 

 is known from no locality other than within the city limits of 

 Bangkok. 



