176 



Memoirs of the Indian Museum. 



[Voi,. II, 



character. The plates of the ventral surface, however, show no sign of order. In 

 both specimens there is a pigmented ring on either side of the mid-dorsal line ; this is 

 very plain in C 4. These rings also occur in the type v; they therefore seem to 

 be a constant part of the disorderly character. 



Type w {medium and orderly) — 



Fish of this kind occur in every community— A 3, 5; B i, 2, 3, 5, 6, 7; C3; 

 D I, 3, 4. There is some variation in the breadth of the disk. B 5 approaches the 

 broad type, and D 3 approaches the narrow type in this respect. The separation of 

 the groups according to the shape of the disk is therefore not quite distinct, and yet 

 one cannot believe that if a large collection were available they would be evenly dis- 

 tributed about a single mean as regards their breadth. Moreover, after considering 

 the diagram (text-fig. 7) it can scarcely be doubted that there would be three means. 



Measurements in millimetres. 



Community. 



Specimen. 



Length. 



Breadth. 



B. 



L. 



Nasal 

 spine. 



Eye. 



S. 

 E. 



A 

















Depth 200 fms. 



A I. 13014 



49 



25 



51 



4 



8 



50 



Lat. 11° 31' 40" N. 



A 2. 13015 



50 



25 



50 



4 



8 



50 



Long. 92° 46' 40" E. 



A3. 13018 



29 



21-5 



74 



2-5 



5 



50 



Green mud, 56 F. 



A4. 13016 



275 



14-5 



53 



2-5 



4*5 



55 



Year 1890 



A 5. 13020 



27 



20-5 



76 



2-5 



5 



50 



B 



Depth 405 fms. 



Bi. 134 



35 



28 



80 



3-5 



6 



57 



Lat. 13° 27' 00" N. 



B2. 132 



40 



29-5 



74 



4 



7 



57 



Long. 93° 14' 30" E. 



B3- 135 



36-5 



26-5 



7i 



4 



7 



57 



Green mud, 48 F. 



B4. 129 



58-5 



28-5 



49 



4-5 



9 



50 



Year 1896 



B6. 13Ô 



39 



29 



74 



4 



7 



57 





B5-I3I 



38 



32-5 



85 



3-5 



6 



57 



C 

 Depth 185 fms. 



B7- 133 



37 



28-5 



77 



4 



7 



57 



Ci. 286 



65 



36 



55 



5 



10 



50 



Lat. 13° 17' 15" N. 



C2. 290 



43 



31 



72 



3-5 



7 



50 



Long. 93° io'25''E. 



C3. 289 



27 



20 



74 



2-5 



5 



50 



Sand, 53 F. 



C4. 288 



39 



28-5 



73 



3-5 



6 



57 



Year 1897 

















D 

















Depth 27g fms. 



Di. 1123 



40 



29 



72 



4 



7-5 



53 



Lat. 10° 21' 00" N. 



D2. 1121 



42 



39 



93 



4-5 



8 



56 



Long. 92° 46' 15" E. 



D3. 1124 



36 



24 



67 



3-5 



7 



50 



Green mud, 40 F. 



D4. 1122 



34-5 



26 



75 



4 



7 



57 



Year 1904 



D5. 1125 



37 



34 



92 



4 



' 



57 



