42 IOWA STUDIES IN NATURAL HISTORY 
Scolopendra alternans Leach 
Trans. Linn. Soc. London, XI (1812), p. 383. 
This is a characteristically West Indian species which, in 
general, is more abundant on the islands than the preceding 
species. In general appearance the two species are similar and 
both attain a maximum length of about 200 mm. S. alternans 
may be distinguished from S. subspinipes in having numerous 
spines on the third joint of the anal legs in place of the two 
larger ventral ones in the latter species; also in having dorsal 
spines at the end of the third joint of the penult legs where 
S. subspintpes has none. 
S. alternans has been recorded from Antigua by Pocock (Jour. 
Linn. Soe. London, XXIV [1893], p. 458). It has not as yet 
been noted from Barbados, although it in all probability occurs 
there. 
Order GEOPHILOMORPHA 
Family Mecistocephalide 
Mecistocephalus macillaris (Gervais). 
Geophilus maaillaris Gervais, Ann. Sci. Nat., ser. 2, VII (1837), p. 52. 
This is also a tropicopolitan species. It is the only member 
of the genus known from South America and the West Indies. 
It is probably a more abundant form than records indicate, as 
it is small, commonly measuring well under 40 mm. in length, 
and usually is found buried in the earth. It is not infrequently 
found in the soil about plants imported to the United States 
from South America, the writer having identified specimens 
thus taken at quarantine at New York, Philadelphia and Wash- 
ington, D.C. It has also been found in botanical gardens at 
Hamburg and Paris, and was first described from a specimen 
found in the latter locality. 
One specimen taken at St. Michaels, near Bridgetown, Bar- 
bados, by D. Stoner in May, 1918. 
DIPLOPODA 
As in the case of the chilopods, very few kinds of diplopods 
are as yet known to occur on Barbados and Antigua, only four 
species having been recorded. The diplopod material of the 
present expedition examined by the writer was all taken on 
Barbados by Prof. Stoner and represents two of these species, 
