No. 3 (1922) GREY MULLETS OF TUTICORIN 83 



characters, there would seem little justification for regarding them 

 as distinct species; the form of the head, and the proportion of the 

 eye to the head are the only features by which the two seriously 

 differ. For this species, as a laboratory instruction, I have been in 

 the habit of giving "flat head, and no special peculiarities" as 

 features for its identification. Details are given below ■- 



Adipose lids. — Present; anterior one narrow, posterior broader; 

 the latter occasionally even reaching to the pupil. 



Interorbital space— Flattened ; l£4 to 2 times the diameter of" 

 the eye across. 



Uncovered chin space. — Moderately wide ; constricted about its 

 middle ; the anterior part rounded. 



Mandibular angle. — The angle between the mandibular rami is 

 "normal," that is, HO to 112 degrees. 



Preorbital bone. — Scaled; it is strongly bent and serrated 

 posteriorly and ventrally. 



Maxilla. — The end of the maxilla is distinctly visible. 



Pectoral fin: Rays. — The normal number of fin rays in the 

 pectoral fin is 16 ; one specimen examined showed 17 rays. 



Extent. — The fin reaches as far as the 8th scale 

 of the lateral line ; in one specimen, it reached to the 9th, while in 

 one other it only extended to the 7th. Giinther gives the extent as 

 the 8th scale, and Day as the 7th. 



Axillary scale. — No elongated scale is present in 

 the axil of fin, but sometimes a short stumpy scale is found. 



Lateral line series.— Most commonly 31 scales are found in 

 the lateral line, but 30 and 34 are the extremes met with in speci- 

 mens examined. Day credits this species with 29 — 31 scales and 

 Giinther with 33 — 35. 



Lateral transverse series. — 10 or II rows of scales may be 

 present on either side of the body; some specimens have II, others 

 10, on each side, while others again shew 10 on one side and II on 

 the other. The differences observed seem to depend on the rela- 

 tive prominence of an additional series, which is nearly always 

 met with near the mid-ventral line; this series may be so short as 

 to be inadmissible as a series, or it may rank as a complete one, 

 adding to the side on which it occurs. Both Giinther and Day 

 give II rows for this species. 



Origin of the dorsal fins.— The I Oth and 21 st scales of the 

 lateral line may be regarded as those corresponding to the origin 



