10 



Stenopkora robusta may be distinguished from the other two species 

 of Stenophora known from the United States by the following key: 

 A. Small species, average individuals under 170 u\ body robust; 

 deutomerite broad, oval and regular, its greatest width 2 to 2,25 

 in the length of the deutomerite ; body rather rigid. 



S. robusta nov. spec. 

 AA. Large species, average individuals over 250 /*, maximum length 

 nearly 1 mm; body elongate; deutomerite cylindrical or flask- 

 shaped; greatest width 3,5 to 5 in the total length, (in flask-shaped 

 individuals, rarely 2): body very flexible. 

 B. Host Diplopoda. 



& larvata (Leidy). 



BB. Host the cricket, Oryllus abbreviatus. S. erratica Crawley. 



The two species S. larvata and S. erratica are separated here on the 



B 



Fig. IB. Drawn from a living specimen, showing the cup-like depression in the 



epicyte at the end of the protomerite. This was observed in about one-fourth of 



the individuals. Length, 173 ». 



basis of host only, as Crawley in his original description 1 makes the 

 suggestion that S. erratica may be but an aberrant form of S.julipasiUi 

 (Leidy) resulting from the development of the spores of that species in 

 an unusual host , the cricket. Accordingly this species must be more 

 fully studied. The only other species with which S. robusta might be 

 confused is Amphoroides fontariae Crawley. This species according to 

 Crawley 2 at times assumes a shape somewhat similar to that of S. ro- 

 busta. This form of Ampli oroides fontariae however is without the ap- 

 parent pore in the protomerite and does not have the correct measure- 

 ments for S. robusta the protomerite being from 4 to 4,25 in the deuto- 

 merite. 



In view of the variety of gregarines , of which nine species have 

 been referred to the genus Stenophora, which have been found in Euro- 

 pean Diplopods, it seems well to list the North American species known 



i Proc. Acad. Nat. Sci. Philad., Vol. L1X, Pt. II, p. 221, 1907. 

 2 1. c, Vol. LV, Pt. I, pi. I, fig. 14, 1903. 



