No. 3 (1922) GREY MULLETS OF TUTICORIN 93 



The length of the first spine of the first dorsal fin is equal to, or 

 a little greater than the postorbital part of the head. The dorsal 

 spines are strong. 



The third spine of the anal fin is about Vj, of the length 

 of the head, a little more or a little less. 



Colour. — There are no special features of colouration to be 

 noted. 



Liza caeruleo-maculata (Lacepide). 

 D. 4 I 1/8. A. 39. L. 1. 39 L. tr. 14. 

 This handsome mullet is common in Silavatturai Lagoon; it 

 may be identified at a glance by the following characters : — 



(1) Dorsal surface of the head slightly convex from side to 

 side. 



(2) A dark bluish-black spot at the upper edge of the base of 

 the pectoral fin. 



(3) The presence of an elongated axillary scale in the axil of 

 the pectoral. 



(4) The pectoral fin reaches to the origin of the first dorsal fin. 



(5) The spines of the first dorsal fin are weak. 



(6) The origins of the anal and second dorsal fins opposite. 



(7) The rows of scales across the body numerous (14). 



(8) The uncovered space at the chin is very narrow or even 

 obliterated. 



The detailed description is as follows: — 



Adipose lids. — Absent. 



Interorbital space. — Slightly convex ; sometimes may be re- 

 garded as a little flattened. Its distance across is as nearly as 

 possible equal to twice the diameter of the eye. Bleeker gives 

 a very wide range of variation here, viz., 1% to 2% times the diame- 

 ter. Day gives it as ^2 the length of the head, which corresponds 

 with Tuticorin specimens. 



Uncovered chin space. — Very narrow, and often practically 

 absent, especially posteriorly, owing to the close approximation 

 or overlapping of the opercular folds. 



Mandibular angle.- ' Normal," i.e., the rami meet at an angle of 

 about 112 degrees. 



Preorbital bone. — Either not at all, or but sparsely scaled 

 serrated posteriorly and ventrally. 



Maxilla. — The end of the maxilla is completely hidden. 



