386 SNODGRASS AND HELLER 



In 1862, Gill (Proc. Ac. Nat. Sci. Phila. 1862, 148) described 

 2 species of Pomacentrus from Cape San Lucas P. rectifrcenum 

 and P. Jlavilatus, the type of each being an immature specimen. 



Later in the same year, Giinther (Cat., IV, 27, 1862) published, 

 from Gill's manuscript, the description of a third species, Pomocentrus 

 analiguttata Gill. This species Gill himself in the following year 

 retracted. 



In 1863, Gill (Proc. Acad. Nat. Sci. Phila. 1863, 215) redescribed 

 P. rectifrcenum and P. Jla vilatus. In these descriptions, based on a 

 greater number of specimens, the difference described between the 

 types of the 2 species is much less prominent. 



Giinther, in 1866 (Fishes of Central America, 445) regarded 

 Gill's 2 types, Pomacentrus rectifrcenum and P. Jla vilatus, as simply 

 2 color forms of the same species, P. rectifrcenum. 



In 1891, Gilbert (Proc. U. S. Nat. Mus. 1891, 554) described the 

 species P. leucorus, distinguished from the other species by having 

 the pectorals tipped with orange (white in alcohol) and posteriorly 

 bordered with white. The type specimens of this species are from 

 the Revillagigedo Archipelago, but the species is abundant also at 

 both Cocos and the Galapagos islands. 



Jordan, 1896 (Fishes of Sinaloa, Proc. Cal. Acad. Sci., 2d Series, 

 Vol. v, 1895 (1896), 474, described as Eupomacentrus Jlavilatus, 

 a very young example from Mazatlan, about f- inch in length. 



In 1899 Jordan and McGregor (Fishes of Revillagigedo Archi- 

 pelago and neighboring Islands, Rep. U. S. Fish Comm.for 1898, 

 282, 1899) recorded from Clarion and Socorro islands, 6 specimens 

 of a Pomacentrus that they identified as P. rectrifrcenum, and 12 

 others that they identified as adults of P. Jlavilatus. 



We have examined this Revillagigedo material and find that, 

 excluding P. leucorus with orange-tipped pectorals, it includes only 

 one species not 2 as identified by Jordan and McGregor. Further- 

 more, we have examined both young and adult examples from 

 Panama which are certainly P. rectifrcenum Gill. The Revillagigedo 

 adults are not the same species as the Panama adults, and the young 

 are neither P. rectifrcenum Gill nor P. Jlavilatus Gill. Hence, we 

 have described the Revillagigedo form as a distinct species Poma- 

 centrus redemptus (Proc. Wash. Acad. Sci., v, 1903, 200, pi. vi). 



At Cocos and the Galapagos islands there occur 2 species of 

 Pomacentrus one is P. leucorus, the other we have described as P. 

 arcifrons (ibid, 202, pi. vn). 



In 1904, Gilbert and Starks (Mem. Cal. Acad. Sci., iv, 141, pi. xxi) 

 described the species P. gilli from Panama. 



