NO. 3 (I922) GREY MULLETS OF TUTICORIN 8l 



(1) The broad and flattened upper surface of the head ; 



(2) the broad and very thick adipose eyelids, which extend 

 some distance across the pupil of the eye; 



(3) the dark blue band across the base of the pectoral fin ; and 



(4) the peculiar shape of the lower jaw, the mandibles bending 

 towards the middle, at the angle of the mouth. 



The detailed characters are enumerated below: — 



Adipose lids. — Present ; very thick and broad, extending to, or 

 even beyond, the edges of the pupil. 



Interorbital space. — Broad and flat ; twice the diameter of the 

 eye across. Both Giinther and Day describe the width of this area 

 as more than twice the diameter of the eye. 



Uncovered chin space. — Wide, and often constricted about its 

 middle. 



Mandibular angle. — The angle between the rami of the lower 

 jaw is comparatively acute, approaching a right angle, and at the 

 angle of the mouth the mandibles turn inwards towards the middle 

 line. 



Preorbital bone. — Scaled and serrated on the posterior and 

 ventral edges ; it is scarcely at all bent, and is not prominent. 



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



Pectoral fin : Rays. — The number of fin rays usually present 

 in the pectoral fin is 17, but one specimen examined gave l6only, 

 while another possessed 18 rays. These latter are exceptional. 

 Day's formula gives 1 5 rays only, but I have never found less than 

 16. 



Extent. — The fin reaches to the 10th to I2th scale 

 of the lateral line, that is, a little short of the origin of the first 

 dorsal fin. This agrees with Day's description, but Giinther places 

 the extremity of the fin at the 8th scale. 



Axillary scale. — An elongated axillary scale is 

 always present in the axil of the pectoral fin. 



Lateral line series. — 42 scales are typically present in this 

 series, but 40, 41 and 43 have been counted in several specimens. 

 Day gives 42 to 44, but Giinther only 38 to 40. 



Lateral transverse series. — 14 complete rows of scales are pre- 

 sent on each side of the body ; this excludes a short series which 

 extends only between the two dorsal fins, where no median series is 

 found. In one case, there were 14 on the right side and 15 on the 

 left. 



