1886.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 485 



We have at present no specimens of this species. The Sicydium 

 antillarum of Mr. Ogilvie-Grant, seems to differ only in the greater 

 prominence of the teeth, a matter subject to variations, perhaps ac- 

 cording to the age, sex, or condition of the specimen. 



9. SICYOPTERUS. 



SiCYOPTERUS Gill, Proc. Acad. Nat. Sci. Phila., 1860, 101 (stimpsoni). 



COTTLOPUS Guicheuot, in Maillard Notes sur FIsle de la E6union, ii, Addenda 9, 1864 



(acutipiiinis). 

 SiCYDiGPS Bleeker, Esquisse d'un Syst^me Natural des Gobioides, 314, 1874 (xon- 



thurus). 

 ?MiCROSiCYDiUM Bleeker, I.e., 314, 1874 {gymnauchen). 



Type Sicyopterus stim/psoni. 



As here restricted, this group would include all the species of Sicy- 

 dium, in which the teeth are trifid, bifid, or (by wearing of the tips) 

 clavate. Having had no opportunity to study the species of this group, 

 we do not know whether this division is a natural one or not. 



ANALYSIS OF THE SPECIES OF SICYOPTERUS. 



a. Head 4 to 5 in length (to base of caudal) ; width of head, J its length ; depth of 

 body, 5| to 6J in length ; scales ctenoid ; teeth in upper jaw curved, tricuspid, 

 trident-shaped, the middle cusp terminal, very short, soon worn away ; dorsal 

 VI-I, 10. Anal I-IO. Caudal rounded ; dorsal spinfis produced in filaments. 



t. [Neck and belly naked ; a double or treble row of small papill3B on the gum 

 beneath the upper lip, without a larger median papilla ; third dorsal spine 

 twice height of body ; second dorsal higher than the body ; scales 60 to 

 64 ; color violet-brown, yellowish in young specimens, shaded with indis- 

 tinct transverse bands of darker; an irregular brown spot on the axis of the 

 pectoral and a broad dark band from the base of the pectoral to the root of 

 the caudal ;. fins violet, clouded with darker; 60 to 64 scales in a longitudinal 

 series.] (Grant) Gymnogaster, 1.5. 



J6. [Neck and belly covered with small scales ; gum beneath the upper lip smooth ; 

 a median papillose tubercle above the maxillary suture; second and third 

 dorsal spines one and a half times the height of body ; second dorsal not as 

 high as body ; scales 78 ; color olive-brown ; anal yellow, with a black and 

 white band along the margin ; membrane of the second dorsal clear, si)Otted 

 with brown ; caudal with a dark and yellow band round the extremity; 78 

 scales in a median series. ] ( Grant) Salvini, 16. 



15. Sicyopterus gymnogaster. 



Sicydium gymnogaster Grant, Proc. Zool. Soc. London, 1884, 158, plate xi, fig, 

 2, and xii, fig. 6 (Mazatlan). 



Habitat. — Fresh waters of the Pacific slope of Mexico. 

 We know this species only from the description an d figure given by 

 Mr. Ogil vie Grant. 



16. Sicyopterus salvini. 



Sicydium salvini Grant, Proc. Zool. Soc. London, 1884, 159, ])late xii, fig. 2 

 (Panama). 



Habitat. — Streams of the Pacific slope of the Istlimus of Panama. 

 This species is known to us only from the description and figure given 

 by Mr. Ogilvie-Grant. 



