PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 647 



purplish reflections; a distinct black blotch on upper angle of operclo, 

 extending on shoulder girdle; inside of opercle, and skin lining shoulder 

 girdle below, largely dusky. A quadrate black blotch on back of tail, 

 extending backwards along bases of upper caudal rays. Fins light 

 yellowish, the dorsal and anal edged with black; tip of upper caudal 

 lobe black. Ventrals whitish. Tongue, base and roof of mouth, and 

 skin of upper branchiostegals black. 



Abundant at Panama; recorded by Dr. Steindachner from Magdalena 

 Bay, Lower California. The types, numbered 291G5, 29278, 29285, and 

 29343, were collected by Mr. Gilbert at Panama. It is known to the 

 fishermen at Panama as Orqueta. 



Indiana Univeesity, November 27, 1882. 



I>E8€BIPTI01V OF A NEW EEI. (NIDEBA CASTANEA) FBOm: MAZAT- 

 I.AIV, MEXICO. 



BY DAVID S. JORDAN AND CHAKLES H. OILBEBT. 



Sidera castanea sp. nov. 



(Sidera jianamensis Jot. & Gilb., Bnll. U. S. Fish Comm. 1882, 106 ; name only ; 

 not Murama panaviensis Steind.) 



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

 length of trunk ; cleft of mouth wide, 2J to 2i in head ; teeth every- 

 where uniserial or nearly so, those on sides of mandible small, com- 

 I)ressed, close-set, subtriangular, directed backwards, about 18 in number 

 on each side ; mandible with about four large canines anteriorly ; upper 

 jaw with the teeth partly in two series, some of the teeth being mova- 

 ble, the others mostly stronger, canine-like, especially anteriorly. Front 

 of vomer with two 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 diame- 

 ter 2 to 2^ in snout; gill-opening one-third wider than the orbit; tube 

 of anterior nostril short, less than half diameter of orbit ; posterior 

 nostril without tube ; occiput not especially elevated, the anterior pro- 

 file scarcely concave (perfectly straight in young 2 feet long). 



Dorsal fin commencing much in advance of gill-opening, becoming 

 unusually high posteriorly, where its vertical height is more than half 

 greatest depth of body ; the length of the longest ray more than great- 

 est depth of body. 



Color light brownish-chestnut, slightly paler on abdomen ; no spots 

 or bands anywhere ; fins without dark margins ; no dark spot on gill- 

 opening or at angle of mouth; no black about eye; head without con- 

 spicuous pores. 



The specimen here described is 44 inches in length; others about 2 

 feet in length agree very closely. 



