2804 Bulletin ^7, United States National Museum. 



backward to a point considerably behind angle of mouth. Origin of dor- 

 sal entirely behind tip of pectorals, its distance from snout i to ^ greater 

 than length of the head. The tip of the tail is compressed, acute, horny, 

 used for defense. Pectoral very short, from a wide base which slightly 

 exceeds length of gill slit. The fin rapidly narrows downward, the longest 

 portion contained 12 to 14 times in length of head. The width of gill 

 slit is about \ head. 

 The following table gives measurements of 4 specimens in millimeters; 



Four specimens were secured, 3 obtained in brackish water at the mouth 

 of a small stream which emi^ties into Panama Bay, the fourth in a fresh- 

 water pond at Miraflores. There is some reason to suppose that they 

 burrow in the mud. 



Pisoodonophis daspilotus, Gilbert, Fishes of Panama, MS. 1898, Panama. 



Page 382. Murwna ophis, Linnaeus, is without much doubt the original 

 OpMchtlms havannensis. The species would therefore stand as — 



(520. OPHICHTHUS OPHIS (Liniifcus). 



Page 396. ShJera castanea, Jordan &. Gilbert, should be removed frpm 

 the synonomy of Lycodontis fimebris. It is ajipareutly a valid species and 

 should be inserted as — 



650(a). LYCODOiVTIS CASTANEUS (Jordan &. Gilbert). 



(MOEENA PrIETA.) 



Tail about as long as rest of body, or slightly longer. Head 2^ in length 

 of trunk ; cleft of mouth wide, 2^ to 2.^ in head. Teeth every whei'e uui- 

 sei'ial or nearly so, those on sides of mandible small, compressed, close set, 

 subtriangular, directed backward, about 18 in number on each side; man- 

 dible with about 4 large canines anteriorly; upper jaw with the teeth 

 partly in 2 series, some of the teeth being movable, the other mostly 

 stronger, caninelike, especially anteriorly; front of vomer with 2 very 

 long, slender canines, behind them a single series of small teeth; teeth 

 all entire. Eye large, slightly nearer tip of snout than angle of mouth, 

 its diameter 2 to 2i in snout; gill opening + wider than orbit; tube of 

 anterior nostril short, less than V diameter of orbit ; posterior nostril with- 



