1112 The American Naturalist. [December, 
Pocock informed me that the collector of the Ceylon species reported 
that the animals were saltatory. This apparent jumping motion, is 
caused by vigorous wriggling of the body. At other times they crawl or 
run after the manner of other Diplopoda, but are more fleet. Strangely 
enough, one of several genera of Spirostreptidg found in Liberia is also 
very fleet and has the habit of throwing itself by vigorous wriggling in 
the same way as Stemmatoiulus. In Liberia I collected three well- 
defined species, here referred to Stemmatoiulus, but noticed no differ- 
ences in habitat or habits. All were found among fallen leaves and 
decaying vegetable debris in deep forests or other moist and deeply 
shaded localities, or rarely in heaps of rubbish in open places. 
Structurally considered, these Liberian species show many characters 
or combinations unique among recent Diplopoda. It will not be pos- 
sible to separate satisfactorily the ordinal, family, generic and specific 
characters in this group until the American and Indian forms are 
better known, and the following subordinal description will probably 
need modification when further investigation has been made. 
STEMMATOIULOIDEA, new Suborder. 
Body fusiform, distinctly compressed laterally. 
Labrum tridentate, with a median tooth. 
Eyes of one or two very large ocelli. 
Mandibulary stipe with cardo distinct, subequal in size with the 
stipe. 
Hypostoma present, large. 
Mentum entire, very short. 
Promentum broad, longer than the mentum. 
Lingual lamine distinct, very large, transversely striate; lingual 
lobes provided with sense-cones. 
Median lobe well-developed, without styliform processes, 
Segments not divided by a constriction into anterior and posterior 
subsegments; the suture inconspicuous or wanting; dorsally with a dis- 
tinct median suture and four pairs of setiferous punctations; surface 
divided by longitudinally oblique impressed lines into narrow areas. 
Repugnatorial pores present, subdorsal, located in the anterior part of 
the segments. 
Pleurs incompletely adnate or nearly free from the tergites. 
Pedigerous lamin all free, of two different shapes. 
Legs eight-jointed, except the first two pairs. 
Seminal opening of males through an unpaired two-jointed, external 
duct inserted behind the second pair of legs, which are greatly 
modified. 
