PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 349 



MiUi- 

 moters. 



lOOths of 

 lenj'th. 



Extreme length ....... 



Lenght to end of middle caudal rays . 

 Body : 



Greatest heinht 



Greatest width 



Least height of tail 



Head : 



Greatest length 



Greatest width 



SVidth of iuterorbital area 



Leugt li of suout 



Lriigth of maxillary 



Diiimeter of orbit, iongitudinal . . 

 Dorsal (spinous) : 



Distance from suout 



Length of base 



Greatest height 



Dorsal (soft) : 



Length of base 



Height at longest ray 



Anal: 



Distance from snout 



Length of base 



Height at longest ray 



Caudal :" 



Len gth of middle rays 



Pectoral : 



Distance from snout 



Length 



Ventral : 



Distance from snout 



Length 



Dorsal 



Anal - 



Teutral 



!N umber of scales iu lateral line 



33 

 10 



23 



14 



VI-[VIIJ,17 



IG 



6 



[58] 



Peristedium miiiiatum, new species. 



Total lengtli of type (No. 26023) 300 millimeters. 



The greatest width of the body (20) is equal to its greatest height 

 (19.5), being one-fifth of its total length wiihont caudal. The general 

 armature of the body is much like that described by Giinther under 

 Pcristctlms hrevirostre.* The number of plates between the gill-opening 

 and the base of the tail is from twenty-seven to twenty-nine. There are 

 four series of spiny plates on each side, the spines of the abdominal 

 series becoming very weak and obsolete towards the tip of the tail. 



The length of the head (10.15) is two-tifths of the total length without 

 caudal. The length of the preorbital processes (7) is contained about 

 three times and one-half in the distance from their extremities to the 

 anterior margin of the orbit. The iuterorbital space is deex)ly concave, 

 its width (0.75) contained between six and seven times in the length of 

 the head. Protuberance on the forehead very slight. The length of 

 the snout (22.5) is more than half that of the head (in young less). The 

 diameter of the eye [do) is contained between six and seven times in the 

 lengtli of the head. There is one pair of spines upon the upper surface 

 of the snout behind the base of the preorbital processes, and another 

 larger pair upon the preorbital processes, one upon each. The ridge of 

 the preoperculum terminates in a depressed, short, sharp-pointed spine. 

 The number of small tentacles upon either side of the lower jaw is about 

 * Cat. Fish. Brit. Mus. ii, 18G0, p. -218. 



