COLLEMBOLA 303 



now before us seems to be by far the most plentiful and widespread springtail in the 

 Sandwich Islands. 



(i) N^eauura citrouclla, sp. nov. (PI. IX. figs. 20 — 27). 



Length 2 mm. Colour in life' light orange. Head as long as broad. Antennae 

 half as long as head (fig. 21), relative length of segments as 5 : 7 : 4 : 6 ; a groove at 

 the distal end of the second segment (fig. 2-j gr), a reduced sense-organ on the third 

 segment (hg. 27 a. 0. 3), the characteristic antennal organ on the fourth segment consisting 

 of several small globular prominences closely grouped together- (fig. 27 a.o. 4). Ocelli 

 three on each side (but in some specimens two only can be distinguished); apparently 

 degenerating and without pigment (fig. 26). Post-antennal organ rudimentary, consisting 

 only of a inw extremely minute prominences in a groove of the integument (fig. 26). 

 Six prominent globular tubercles on each body segment (fig. 20). Feet with elongate 

 setae and long evenly curved claws, each with a single tooth and a small basal 

 appendage (fig. 22). Vestiges of the spring (fig. 23/) can be seen on the ventral 

 aspect of the abdomen. 



A dissection of the jaws of this species (fig. 25) shows that the mandibles have 

 a series of sharp teeth at their extremity, of which the proximal is much the largest 

 (fig. 25 d), while the maxilla possesses a distinct galea with teeth (fig. 25 c, ga), 

 a lacinia fringed with curved setae (fig. 25 c, /a), and a small conical palp (fig. 25 c, /). 

 The maxillulae (fig. 25 a, b, mxl) are very delicate, but quite distinguishable. 



This species comes nearest to the Oriental N. fortis, Oudemans', which has six 

 ocelli but no post-antennal organ and no tooth on the claw, and the Alaskan N. ornata 

 Folsom', which exhibits the degraded ocelli of the present species, but is white in 

 colour, and has the tooth of the foot-claw basal in position. In general aspect our 

 insect resembles N. tasmaniae Lubbock', from Tasmania, of which few structural details 

 are given. The latter species, however, is purplish in colour. 



Hab. Oahu : Waianae Mts., 2000 ft., Perkins, April 1892, Sept. 1896, under 

 bark of Acacia : Honolulu, July 1896. — Maui: Haleakala, 5000 ft., Perkins, May 1896. 



There can be little doubt that the five species described in this paper represent 

 but a fraction of the springtail-fauna of the Sandwich Islands. 



' I am indebted for this character to a MS. note by Mr Perkins. All the specimens are now dried up 

 and white. It is very likely therefore that the breadth of the insect is relatively greater than shown in fig. 20. 



^ For an account of these organs see Absolon, Zool. Anzeiger, xxiv. 1901, pp. 575 — 585, and Borner, 

 Zool. Anzeiger, xxv. 1902, pp. 92 — 116. 



^ Weber's Ergebn. Reise Nederl. Ostindien, 1890, p. 91. 



* Proc. Washington Acad. Sci. iv. 1902, p. 89. 



'" Journ. Linn. Soc. (Zool.) xxvii. 1899, p. 335. 



39—2 



