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Transactions. 



sides. The remaining eight individuals preserved in alcohol 

 exhibit the same pattern.* 



It will be evident, then, that the colour jDattern is quite dif- 

 ferent from that of H. antipodum (2), though we do not know 

 with certainty what are the true colours of this leech when 

 alive. But as there are differences of greater imjDortance in 

 the internal anatomy, the distinctness of the two species is con- 

 siderable. 



Dimensions. — The living leech when fully extended — i.e., 

 with both its suckers adhering to the table-top — measured 

 85 mm., and when contracted 25 mm., with a diameter of 7 mm. 

 in the latter condition. The length when killed and preserved 

 is now 70 mm. ; the greatest breadth, which is a little behind 

 the middle of the body, is 5 mm., but this is only slightly greater 

 than the diameter elsewhere ; and thickness 3 mm. The sucker, 

 about 4"5 in diameter (fig. 7). 



Of the remaining eight, the measurements are as follows 

 (Nos. 2-5 were killed in alcohol, Nos. 6-9 in corrosive sub- 

 limate) : — 



Measuremerits in 3Iillimefre9. 

 No. 



1 



2 



3 



4 



5 



6 



7 



8 .. 



9 



The sucker is not quite circular, having the transverse dia- 

 meter slightly greater than the longitudinal. 



It will be seen that the specimens vary from rather less than 

 2 in. to nearly 3 in. in a preserved state, with a breadth of 

 approximately ^ in. No. 2 on the list is distended, probably 

 with blood. 



The leech is long and narrow, with a moderate sucker. 



External Anatomy. — This was studied in specimen No. 1 

 when freshly killed. 



There are the usual five pairs of eyes, on the annuli charac- 



* Four, killed in corrosive sublimate, show the olive-brown as dark- 

 brown, the yellow bands as pale-primrose, the belly dirty-white. Four 

 were killed in alcohol : in these the ohve bands are now dark bluish-{2:rey, 

 the yellow bands are very pale yellowish-brown. In all the median band 

 is ])aler than the two lateral dark bands. 



