1884.] GENERA. SICYDIUM AND LENTIPES. 159 



root of the caudal, both more or less indistinct in adult specimens. 

 Fins violet, clouded with darker. 



The largest specimen measured 4% inches. 



Hub. Mazatlan. 



Six specimens — adult, halt-grown, and young. 



5. Sicydium salvini, sp. n. (Plate XII. fig. 2.) 

 D. 6*. A. i. L. lat. 78. 



Teeth in the upper jaw tricuspid ; the middle cusp, which is 

 situated at the anterior end of the tooth, is very short and soon 

 becomes worn away. 



Gum beneath the upper lip smooth ; a median papillose tubercle 

 above the maxillary suture ; upper lip with a small median notch ; 

 maxillae contain au angle of about 75° ; horizontal teeth con- 

 spicuous. 



The total length of the body (without the caudal) is four and 

 three quarter times the length of the head ; the width of the head 

 is greater than the height and three quarters of the length. The 

 height of the body is contained six and a quarter times in the length. 

 Scales ctenoid, those on the neck and belly smaller than those on 

 the body and tail. The diameter of the eye is contained five and a 

 half times in the length of the head and twice in the iuterorbital space. 

 The length of the pectoral is rather greater than that of the head. 

 The second and third dorsal spines are subequal and produced into 

 short filaments, one and a half times the height of the body ; second 

 dorsal not so high as the body. Colour olive-brown ; anal yellow, 

 with a black and white band along the margin ; membrane of the 

 second dorsal clear spotted with brown ; caudal with a dark and 

 yellow band round the extremity. 



Total length 4f inches. 



Hab. Panama. 



One adult specimen. 



6. Sicydium acutipinne, Guich. 



Cotylopus acutipinnis, Guich., in Mallard, Notes sur ITsle de la 

 Reunion, ii. Add. C, p. 10 ; Bleeker, Arch. Neerl. ix. p. 313. 



D. 6^. A.i. L. lat. ca. 56. L. trans, ca. 18. 



Teeth in the upper jaw tricuspid, comparatively large. Gum 

 beneath the upper lip smooth ; no median papilla above the 

 maxillary suture ; no cleft in the upper lip ; maxillae contain au 

 obtuse angle ; horizontal teeth inconspicuous. 



The total length of the body (without the caudal) is five and two 

 thirds the length of the head ; the height and width of the head are 

 subequal and rather less than two thirds of the length ; the height 

 of the body is about one seventh of the total length. Scales strongly 

 ctenoid on the sides of the body. Head, neck, and belly naked. 

 The diameter of the eye is one fifth the length of the head ; maxilla 

 extends to the vertical from the anterior margin of the eye. The 



