216 



Transactions. — Zoology. 



O. novcc-zealandicc, which I beHeve I have gathered in the bush but never on 

 the coast. 0. sylvicola is recorded by Dana as having been obtained " from 

 moist soil in the bottom of the extinct volcano of Taiamai, twenty miles 

 from the sea, and about the joints of succulent plants," The Brit. Mus. 

 specimen was obtained in the voyage of the Erebus and Terror, and " was 

 found associated with 0. telluris.'" As I have already said, this was pro- 

 bably on the edge of the bush near high-tide mark. 



It is singular that Prof. Dana should have described the male only of 

 0. sylvicola, for it has been frequently noticed, both by Professor Hutton and 

 myself, that males are extremely rare. The examination of a large number 

 of specimens of terrestrial Orchestice gathered in the bush and at the roots 

 of plants in many localities distant from the sea, leads me to the conclusion 

 that varying forms of the same species have been described under three 

 names, namely, 0. nov<x-zealandi(f., iera., 0. sylvicola, {era.., and 0. tenuis, 

 fern. The principal characters employed in the identification of these 

 species are : — 



(1) the length of the superior antennae ; (2) the length of the inferior 

 antennae, together with the relative length of the flagellum to the peduncle, 

 and the relative lengths of the ultimate and penultimate joints of the 

 peduncle ; (3) the sizes and shapes of the gnathopoda, and particularly of 

 their terminal joints; and (4) the relative lengths of the three posterior pairs 

 of pereiopoda. If the characters of the three species are arranged in tabular 

 form it will be found that there is very little to choose between them. 



Female. 



0. sylvicola. 



novcB-zealandicB. 



0. tenuis. 



Upper antennas 



Eeaching beyond the 

 extremity of penulti- 

 mate joint of lower 



Eeaching beyond ex- 

 tremity of penulti- 

 mate joint of lower 



About as long as base 

 of inferior 



Inferior antenna . , 



Flagellum .. 



Ultimate joint of 

 peduncle 



More than half aa long 

 as body 



As long as peduncle 



Twice as long as penul- 

 timate 



More than half as long 

 as animal 



Longer than peduncle 

 and spinous 



Slightly longer than 

 penultimate 



About half as long as 

 body 



Much longer than base 



Posterior pereiopoda 



Third pair nearly as 

 long as fourth 



Third pair as long as 

 fourth and fifth 



Very unequal ; increas- 

 ing regularly in length ; 

 fifth pair nearly twice 

 longer than third. 



I have not compared in the table the characters of the gnathopoda, but 

 if these are examined and the wording of the descriptions rendered uniform, 

 it will be found that there is little to choose among them. Further, the 



