the Early Stages oj Palfcostonia scliiiieii. 197 



end ; tibia and tarsus similarly darkened. Middle and 

 hind : coxa and femur pale, the latter with two broad ill- 

 defiued blackish bands, the one beyond the middle, the other 

 a little remote from tip ; tibia very slightly suffused, with an 

 orange end-spine to hind pair. AH the tarsi are blackened 

 and bear bristly hairs ; the claws are well developed, black, 

 with a minute spine or accessory claw at the base of each. 



Abdomen (figs, 16/ 17). — Somewhat flattened sideways; 

 viewed dorsaliy the segments are dull brown, darkened a 

 little on the sharply defined distal margins : the segment 

 before the genital ones has a fringe of longish yellow hairs. 

 In side-view the segments are pale for about the proximal 

 two-thirds, the rest is as the dorsum. The venter is strongly 

 differentiated from the sides, ridged at each distal edge of a 

 segment ; the whole is densely scaled or pollinated, the 

 raised distal margins being orange and brown, the depres.sed 

 interspaces silvery. The lower genital segments are rather 

 shining orange and chitinized, the upper ones are like tne 

 dorsum. 



Length about 3| mm. Wing-length about 5| mm. 



VII. Geographical Considerations, Affinities, etc. 



Three species of Paltustoma are known : P. superbiens, 

 Schiner, from Colombia, known only in ($ sex ; P. schineri, 

 \yilliston, the subject of this paper, St. Vincent and Trinidad, 

 both sexes now known ; and P. bellardii, Bezzi, from Mexico, 

 known only in $ sex. 



It is worthy of note that P. schineri occurs in both 

 St. Vincent and Trinidad, though the two islands belong to 

 completely difterent formations. St. Vincent is one of the 

 volcanic chain of the Antilles, while Trinidad is merely 

 a detached fragment of the South- American continent. 

 St. Vincent is roughly 150 miles north of Trinidad, and 

 there is an unbroken gap of neai'ly 90 miles between Trinidad 

 and Grenada, the southernmost and nearest of the Antilles. 



Bezzi {op. cit, 1913, p. 72), in mentioning the deductions 

 which have been drawn from the geographical distribution of 

 Blepharoceridaj, remarks that there are as yet many lacunie 

 in our knowledge, and that many additional forms will 

 prabably be brought to light in the great continental 

 mountain-ranges and in those of many islands. The present 

 writer would certainly endorse the opinion that this possi- 

 bility exists. With reference to the Antilles in particular, 

 any one who has viewed these mountainous islands, even 



Anil, cO Alog. JS. Hist. Ser. b. Vol. xv. 14 



