APORODESMUS. 
21 
horizontal carinae suggest the Pterodesmidae, but the presence of four 
longitudinal rows of distinctly more prominent areas or granules 
renders diagnosis easy. Although Mr. Pocock desired to call this 
genus Aporodesmus, the pores are present as stated under the family, 
but are difficult of determination on account of the fact that the 
whole dorsal surface is covered with a fine bloom or villosity. All 
poriferous carinae are four-lobed except those of the fifth segment. 
Last segment truncate at apex and with a distinct rounded lobe on 
each side. 
Genus Tridesmus, nov. 
Type Tr. sectilis, sp. n., from Porto Rico in the Berlin Museum. 
Similar in size and shape to the preceding, but with the dorsal sculp- 
ture less defined ; the poriferous segments are three-lobed like the 
others, to the fifteenth. Segments 15-19 are obscurely four-lobed. 
The posterior area of poriferous carinae is much enlarged and some- 
what produced, instead of rounded as in Docodesmus. Last segment 
very small, triangular, entire, rounded at apex, and scarcely exceed- 
ing the produced carinae of the next preceding ; the sinus of the 
nineteenth segment is also much nairower than in Docodesmus. 
Family PTERODESMID^ Cook, 1896. 
American Naturalist XXX, p, 417. 
All the members of this family are distinguished by the possession 
of very broad, nearly entire, radiately impressed carinae, and by the 
location of the pores in the anterior part of the carinae, sometimes 
near its anterior edge. The antennae are short and strongly clavate. 
Genus Aporodesmus Porat, 1894. 
Bih. K. Sv. Vet-Ak. Handl. XX, No. 5, p. 41. 
To this Porat refers three species, probably representing as many 
genera. The author bases his genus on Polydesmus gabonicus Lucas, 
but does not seem to have examined the type, without which precau- 
tion identification is mere conjecture, for Lucas’ descriotion will apply 
to many of the Pterodesmidae. If the view be taken that the type of 
Aporodesmus is not necessarily gabonicus, but rather the form which 
Porat calls falcatus, it may prove necessary to place Compsodesmus 
Ck. as a synonym of Aporodesmus, but as the copulatory legs, pores 
and other important characters of falcatus are still unknown, such a 
reduction might easily prove a mistake. In the meantime two forms 
which Porat has distinguished and figured under gabonicus may be 
safely laken up as good species under the names suggested, Aporo- 
desmus falcatus , sp. n., and A. subrectangulus , sp. n. According to 
Porat tlie seventh joint of the antennae is much shorter than the sixth, 
and in the African ‘ ‘ Cryptodesmidae ’ ’ the fifth joint of the antenae 
