1908.] 



Records of the Indian Museum. 



'2'?>7 



Measurements. 



I 



2 



3 



Length 

 Width ,, 

 Length , 



4 

 6 





7 

 8 





9 

 10 





II 





12 





13 



14 

 IS 

 16 



17 

 18 



Width ,' 

 Length , 



19 



j> ) 



20 



> J ) 



21 





22 



ji ) 



of eye . . 



,, at cornea 



cornea 



antennular ped 



first joint 



second joint 



third , , 



antennal scale 



carapace 

 , exposed part of 

 thorax. 



I St pleon segment 



2nd 



3rd 



4th 



5th 



6th 



6th 



telson to base of 

 terminal spine. 



telson to tip of ter- 

 minal spine. 



telson to extreme 

 apex. 



inner uropod 



outer ,, 



23 



Total length- 

 of telson. 



-rostrum to tip 



Macropsis slabberi. I Macropsis orientalis. 



Actual 



length in 



mm. 



•24 

 •19 

 •92 



■52 

 •19 

 •21 

 •82 



i-;o 

 •25 



•30 

 •34 

 •39 

 •43 

 •45 

 •79 

 •36 



■37 



•44 

 •49 



•92 

 i-i8 



Percent- 

 age of 

 length 

 from 

 rostrum 

 to tip of 

 telson. 



17-4 

 4-8 



3*9 

 i8-6 

 IO-5 



3-9 



4'2 



i6-6 



30-3 



6-0 

 6-8 



7-9 

 87 

 9-1 

 i6-o 

 7-Z 

 7-5 



9-0 



9-9 



i8-6 

 23-9 



Actual 



length in 



mm. 



•52 



•25 

 •17 



•67 

 •32 



•^5 

 •20 

 •92 

 1-90 

 •44 



•33 

 •36 



•2,9 



•42 

 •46 



•67 

 •45 

 •42 



•47 



■94 

 1*27 



Percent- 

 age of 

 length 

 from 

 rostrum 

 to tip of 

 telson. 



9-2 



4-4 

 3-0 



II-8 

 5-6 



2-6 



3-5 

 16-3 

 33-6 



7-8 



6-0 

 6-4 

 7-0 

 7*4 

 8-1 

 1 1 -8 

 8-0 

 7-4 



8-3 



I2'0 



1 6-6 



22-; 



4'94 



5-65 



Carapace. — The carapace in M. orientalis is slightly longer pro- 

 portionally than in M . slabberi, and correspondingly broader. The 

 front part is more evenly rounded and consequently less produced 

 in the former than in the latter species (fig. i) . 



Pleon. — The measurements 11 — 16 in the above table of the 

 segments of the pleon of the two species show that in M. slabberi 

 the segments are proportionately more elongate than in M. orien- 

 talis. Especially is this so with the sixth segment which in the 

 former species is one-and-three-quarter times as long as the fifth, 

 while in M. orientalis it is less than one-and-a-half times that 

 length. At the same time the measurement 17 shows that the 

 sixth segment of the pleon is relatively narrower in M . slabberi 

 than in M. orientalis, and that the rest of the body is correspond- 

 ingly narrower in the former species. 



