Species of Three -opined S irUehicks. 137 



2. Oastrosteua a^gerieusia. 

 Gastrofteua altjeriensis, Sauvjigp, N. Arch. Mu8. Paris, x. 1874, p. 17. 



Depth of" botly '"^^ to 4.\ in the length, lengtli of head '.i to 

 3'^. Snout as U)ng as or a little shorter than eye, the diameter 

 of which is 3 to ',\}s in the Icn^^th ot" head ; interorbital widtli 

 4 to 4^ in the length of head. Usually 2 or ii bony plates 

 «bove the ascending process of the pelvis ; naked area in 

 front of |)ectoral small; pelvic plate usually notched in front, 

 its breadth l.\ to 2^ in its length, which is ;^ to | of the 

 length of head. Dorsal with 11 or 12 soft rays, anal with 8 

 to lU ; origin of first dorsal spine equidistant from the 

 vertical through the bases of the pectoral ami pelvic fins ; 

 second spine g to ^ the length of head ; pectoral extending to 

 or a little beyond the vertical from the second dorsal spine ; 

 pelvic spines j to ^ the length of bead. 29 vertebrae. 



JJab. Algiers. 



Tiiirteen specimens, 38 to 55 mm. in total length, and a 

 number of smaller ones not included in the description. 



1 am indebted to Dr. Giinther for calling my attention to 

 the reduced number of vertebrae in this form ; I count the 

 i-ame number in two specimens. 



3. Gastroateus aantce^annce, sp. n. 



GoAterosteus tcilUamsoni (non Girard), Jord. & Everm. Bull. U.S. Xnt. 

 Mu8. xlvii. 1890, p. 750. 



Depth of body 3^ to 4 in the length, length of head 3^. 

 Snout as long as eye, the diameter of which is 3^ to 3^ m 

 the length of head ; interorbital width 5 in the length of 

 liead. Sides of body without bony plates (rarely with 2 or 

 3 anteriorly) ; naked area in front of pectoral very small; 

 pelvic plate notched in front, 1^ to If as long as broad, its 

 length i? the length of head. Dorsal with 10 or 11 soft rays, 

 anal with 6 or 7 (8) ; origin of first dorsal spine well behind 

 the base of pectoral and only slightly in advance of the base 

 of the pelvics ; second spine 5 to :^ the length of iiead ; 

 pectoral extending to or nearly to the vertical from second 

 dorsal spine ; pelvic spines from | to more than ^ the length 

 of head. 29 vertebrae. 



Huh. Santa Anna River, California. 



Three specimens, 38 to 45 mm. in total length, from 

 Colton. 



I am indebted to Dr. Jordan for a series of examples of 

 the true O. willuimaoni from Santa Clara River. In three 

 of these 1 count 31, 31, and 32 vertebraj, and in all of them 

 the insertion of the dorsal spine is only slightly behind the 

 base of the pectoral. 



