A NEW GENUS AND SPECIES OF ISOTOMIDAE 
(COLLEMBOLA) 1 
! 
By Peter F. Bellinger 
Osborn Zoological Laboratory, Yale University 
In the course of an investigation of the soil fauna of 
some localities in Connecticut 2 , a number of species of Col- 
lembola were found which do not appear to have been 
described. One of these is the subject of the present paper. 
Others will be dealt with in future contributions, as suffi- 
cient material becomes available. 
Micrisotoma, gen. nov. 
Vestiture generally of short simple setae; a few curved, 
strongly serrate setae on all body segments, and some long 
simple setae on the last tergite. Fourth antennal segment 
with blunt, cylindrical sensory hairs dorsally. Postantennal 
organ broadly oval, with a thick border divided into equal 
arcs by four fine partitions. Eyes absent. Unguis and 
empodial appendage untoothed. Tibiotarsus with a distal 
subsegment defined by an indistinct suture. Tenent hairs 
absent. Fifth and sixth abdominal segments ankylosed. 
Manubrium with two pairs of setae ventrally. Dentes 
dorsally crenulate. Mucro bidentate. Pigment absent. 
Generotype : M. achromata, sp. nov. 
Micrisotoma achromata, sp. nov. 
(Plate 2) 
Numerous short, simple, curved setae on the head, ter- 
gites, and appendages. Outstanding, curved, serrate setae 
1 Published with a grant from the Museum of Comparative Zoology 
at Harvard College. 
2 Carried out with financial assistance from the Connecticut Agri- 
cultural Experiment Station. 
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