196 



At the under side of the abdomen in M. Petiverii $, between 

 the rima genitalis and the petiolum, is seen a large, shining sur- 

 face, in which two f-formed furrows and fine costse, curved against 

 each other, enclose a large area broader behind and somewhat broa- 

 der than it is long; this area is open in front, and is bounded be- 

 hind by a — -formed furrow. Before this area are two large 

 shallow, lanceolate or oval depressions diverging in front. — In M. 

 peirensis the corresponding surface displays a somewhat similar area, 

 which however is considerably smaller, especially narrower, almost 

 lyre-formed, longer than broad; within this area, at its base, are two 

 small costse diverging more or less in front, almost in the form of 

 a V. The tibial joint in M. petrensis $ is at the extremity, on 

 the outer side, produced into a long, straight and pointed spur directed 

 forward and reaching to about half the length of the lamina, and 

 lying close upon it; also in M. subterranea <J the tibial joint is 

 provided with such a spur, but in this species it is somewhat shorter 

 and stronger, and has the extremity somewhat bent outwards. 



In M. petrensis C. et L. Koch the front pairs of legs do not 

 differ as much in length from each other as in M. Petiverii, yet 

 enough for the difference to be clearly visible; in one Swedish spe- 

 cimen e. gr. (a ? ad. identified by Dr Koch) the 1 st pair is 7, the 

 2 nd 6'/ 2 , the 3 ld 6 and the 4 th 8*/ a millim. 



Westring states, that in his M. subterranea the anterior tibiae 

 are sometimes provided with a spine on the under side. I have never 

 seen a true M. Petiverii or M. petrensis with spines on the fore- 

 tibise, and therefore conclude, like L. Koch, that the specimens in 

 which Westring found this characteristic, belong to a separate spe- 

 cies. I have lately received such a specimen, a dried ? ad. from 

 Mr Westring, and it seems indeed to be distinguished from M. Pe- 

 tiverii, to which it is closely allied, not only by the different spine- 

 armature, but also by the metatarsi being of the same black or deep 

 blackish brown colour as the tibiae; only the tarsi are paler, of a 

 rusty brown. The form of the vulva cannot be well distinguished 

 in this specimen. I call the species Melanophora tristis ')• 



1) Melanophora tristis N. Nigra, sub-opaca, femorurn anticorum et pal- 

 porum partis femoralis macula magna translucenti basique partis patellaris palpo- 

 rum pallidis, tarsis tantum ferrugineo-fuscis; tibiae 4 anterioribus subtus versus 

 medium spina singula armatse; oculi medii postici non majores quam laterales 

 postici. — $ ad. Long. c:a 7'/ 2 millim. 



Cepbalothorax c:a 3'/ 3 millim. longus, fere longior quam patella + tibia 

 4:ti paris, qui tarso suo pedibus l:mi paris longiores sunt. (Long, pedum l:mi 



