POMACENTRIDAE. 131 
are a little more slender and the suborbital a little narrower. It is possible 
that the strong color marking of the very young of P. arcifrons may serve to 
distinguish them from young of P. rectifraenum. We have no very young of 
the latter. In as much as the posterior paler color decreases with age, it is 
probable that this character would not distinguish larger individuals from P. 
rectifraenum. 
Four specimens, Nos. 3217-19, No. 3219, M. C. Z. 29684 and 3271, M. C. Z. 
29,642, 6 to 63 inches long from Wreck Bay, Chatham Island. 
Pomacentrus flavilatus Gr. 
Proc. Acad. Nat. Sci. Phil., 1862, p. 148. 
Ten specimens 17; to 23% inches long from Acapuleo. M. C. Z. 29540 (5 
specimens). 
One specimen, 13 inches long from Perico Island, Panama Bay. 
Proportional Measurements of four of the largest Acapulco specimens. 
| 
Total length | 56 mm. 51 49 48 
Head in length without caudal 3.11 3 3.06 3.20 
Depth | 2.15 1.96 2.13 | 2.08 
Eye in head | 3. 2.83 | 2.90 2.72 
Preorbital in head 7.2 | 8.50 9.14 | 7.50 
Interorbital in head 3.6 | 3.00 4. Sole 
Dorsal counting last XII, 15 [ Xay 15 XII, 15 | XII, 15 
Anal | II, 13 | II, 13 ELIS 
II, 14 
In the remaining specimens the dorsal rays are constantly 15, and the anal 
rays 13, except in one which has 14. 
The following color note was found with the specimen: — “ Back brilliant 
blue, lower parts chrome; dorsal ocellus black.” 
Color in spirits, top and sides of head to near lower edge of eye and extend- 
ing backward slightly below lateral line to under 6th or 7th dorsal ray abruptly 
purplish brown; below this, sides of head and body yellow, posteriorly brighter. 
The better preserved specimens have centres of scales, on sides of body on the 
purplish area and some on the head pale blue; posterior margin of scales dusky, 
- forming narrow transverse lines becoming fainter posteriorly and ventrally; a 
jet black spot, sometimes ocellated, on upper surface of caudal peduncle; small 
blue spots on scales of the dusky spinous dorsal; a trace of an inframarginal 
pale band also present on spinous dorsal; soft dorsal dusky, with a white area, 
varying in size, on its posterior base, a large jet black-blue margined spot on 
