352 Records of the Indian Museum. [Voi<. VI, 



the animals, their active movements, and the fact that they occur 

 in shallow pools, one is led to believe that they cannot be very 

 widely distributed in India: otherwise, they would have been 

 found before. Most natives to whom I have shown them do not 

 recognize them at all ; but a few persons have told me that they 

 have seen them before, but only during the " rains.' ' 



In colour the animals are chiefly a dull olive-green, with the 

 shield mottled with dark spots. In life, the long filiform endites 

 of the first thoracic limb and in some animals the abdominal seg- 

 ments, have a decidedly rufous tinge. The average length of 31 

 specimens, measured from the anterior end of the cephalic shield 

 to the posterior end of the abdomen (not including the f ureal 

 styles) is 33 mm., that of the styles being 35 mm. The maximum 

 measurements are respectively 40 mm. and 41 mm. A very large 

 specimen measures 80 mm. from the anterior end of the shield to 

 the extremities of the furcal styles. The average length of the 

 shield in the mid-line (eleven specimens) is 24 mm., and its breadth 

 (not flattened out) is 18 mm. Dr. Keilhack (" Siisswasser fauna 

 Deutschlands ") gives 10 — 30 mm. and 9 — 28 mm. for these latter 

 measurements in German examples of Triops^ (Apus) cancriformis. 



I have dissected five specimens, all of which were females : 

 this is in harmony with the fact that in Apus and allied genera 

 males are of rare, possibly seasonal, occurrence. The limbs and 

 appendages of my specimens agree very closely with the admir- 

 able description of those of A. cancriformis given by Professor 

 Bourne {Comp. Anat. of Animals, vol. ii) ; and in most other 

 respects of their external structure the animals appear to be quite 

 similar. 



It is impossible to say without comparison of specimens 

 (which are not available for me) whether this Indian Apus is a 

 new species or not. For the determination of this point I am 

 sending specimens to the Indian Museum. 



1 The substitution of the name Triops for the universally known Apus, 

 though it may be justified in the strict letter of the law, is much to be deprecated 

 as being liable to lead to great confusion. — S. K. 



