38 
SQUAMIPINNES. 
with a bluish border. Dorsal with a black basal band and two similar parallel ones 
on the soft portion. Anal with three dark parallel bands and a brilliant blue margin. 
Ventral with blue membrane between the spine and first ray. Pectorals black. The 
markings disappear rapidly after death. 
Length 4^ inches. 
Zanzibar. 
116. Holacanthus trimaculatus. I 4 " 3 -] 
Holacanthus trimaculatus, ( Lacep .) Cuv. fy Val. vii. p. 196, pi. 182 ; Giinth. Fish. ii. p. 50. 
Zanzibar. Molucca Sea. 
117. Holacanthus imperator. [205.] 
Chfctoclon imperator, Bloch, iii. p. 51, t. 194. 
Holacanthus imperator, Lacep. iv. pp. 527, 534, pi. 12. f. 3 ; Cuv. § Val. vii. p. 180 ; Giinth. Fish. 
ii. p. 52. 
Zanzibar. Indian Ocean and Archipelago. 
118. Holacanthus semicirculatus. [599.] 
Holacanthus semicirculatus, Cuv. Val. vii. p. 191, pi. 183; Less. Voy. Coqu. Zool. Poiss. p. 173, 
pi. 30. f. 3 ; G'unth. Fish. ii. p. 53. 
Zanzibar. East-Indian archipelago. Polynesia. 
119. Holacanthus alternans. [196, 216.] 
Holacanthus alternans, Cuv. Val. vii. p. 193 ; Giinth. Fish. ii. p. 53. 
In old specimens [196] all traces of cross bands disappear, but the darker spots on 
the head and body remain. 
The affinities between II. semicirculatus and II. alternans are of such a nature 
as to call for a renewed examination of fresh specimens to settle the question 
whether the differences between them are not dependent on sexual development 
or age. Specimens with cross bands are 6 inches long, those without bands 10| inches. 
Zanzibar. Aden. Madagascar. 
120 . 
Holacanthus chiysurus. 
[52, 348.] 
Holacanthus chrysurus, Cuv. Val. vii. 188 ; Giinth. Fish. ii. p. 54. 
r-) 12-13 
20-19’ 
A. 
3 
19-20’ 
Immature specimens [52] have a broad yellow band from the last dorsal spine and 
three first rays across the body nearly to the anal. 
Aden. Zanzibar. 
