42 BERYCID^. 



1". Holocentriun diadema. 



Holocentrus diadema, Lacep. iv. pp. 372, 374, iii. pi. 32. f. 3 ; Riipp. 



Atl Fische, p. 84. t. 22. f. 2. 

 Perca pulcliella, Bcnii. Zool. Joiirn. iii. p. 377. pi. 9. f. 3. 

 Holocentrum diadema, Cut. Sf Va/. iii. p. 213; Less. Vol/. Duperr. 



Zool ii. p. 220. pi. 25. f. 2; BMa-y, Amboina &,- Ceram, p. 259. 



D. 11 1 f^. A.^. L. lat. 48. L. transv. 3/7. Vert. 11/16. 



The height of the body is 3f in the total length, the length of 

 the head four times ; the interspace between the eyes is one-liith of 

 the latter. Operculum ^vith two prominent spines, the iipper of 

 which is the stronger, nearly equal in size to that of the prajopercuhun. 

 The foiu'th, fifth, and sixth dorsal spines longest, as high as the 

 longest ray, but shorter than the anal spine. The length of the 

 caudal is one-sixth of the total, both the lobes being equal. The 

 third anal spine is exceedingly strong, and about one-fifth of the 

 total length. The ventral fins reach near to the amis, but the 

 pectorals are much shorter. Red, with eight to eleven silvery lon- 

 gitudinal bands ; the spinous dorsal black, with a white longitudinal 

 band ; the other fins rosc-coloiu'ed. 



Red Sea ; Madagascar ; Ceylon ; Chinese Sea ; Indian Archi- 

 pelago. 



a. Adult. Borneo. 



b. Half-grown. China Seas. Presented by Capt. Sir Edward 



Belcher. 

 e. Half-grown. Tonga Islands. From the Haslar Collection. 

 </. Half-grown. Feejec Islands. Voyage of the Herald. 

 e. Half-growai : very bad skin. Ceylon. From the Collection of 



the Zoological Society. 

 /. Adult. Madagascar. Presented by Dr. J. E. Gray. 

 _f/. Adult : skeleton. India. From Mr. Frank's Collection. 

 h, i. Adult. India. From Mr. Frank's Collection. 



Skeleton. — The general structm-e of the skeleton being the same 

 as in Hohcentnim ruhrum, I give a detailed description of those 

 parts only which exhibit specific peculiarities. 



The fan-Hlie expansion on the vertex is fonned by ten or more 

 radiating branches ; the groove for the posterior processes of the inter- 

 maxillaries reaches a Uttle bej'ond the level of the anterior margin of 

 the orbit. The maxillary and mandibulary bones as in H. viohiceum. 

 The intermaxiUaries are not separated from one another by a notch ; 

 they are thi'ee-quarters of the length of the maxillaries, and have a 

 prominent flat pi'otuberance posteriorly. 



The dentition is formed by villiform bands only ; those on the 

 jaws reach to the posterior extremity of the bones ; they are broad 

 in fi'ont and tapering behind, the intermaxillary banc! less than 

 that of the mandibulary. The vomerine teeth are placed in a small, 

 triangular, equilateral patch, those of the palatiue bones in a narrow 

 band, extending on the pterygoid. The teeth of the pharyngo- 

 branchials form two broad patches on each side, with a few smaller 



