331] STUDIES ON GREGARINES— WATSON 121 



which is only known from the cephalont. Cuenot (1901) says regarding 

 the disposition of the species: 



"Labbe I'a reunit de son propre chef a la G. macroccphala A. Schn.; or, 



cette derniere espece est trop mal connue pour qu'il ait quelque a I'identifier 

 a la mieune ; le grand epimerite en forme de massue de 'macrocephala' n'est cer- 

 tainment pas pareil a celui de 'gryllorum.' 



In a footnote he adds : 



"Schneider ne decrit pas la forme adulte et ne parle pas du nombre de spo- 

 reductes des kystes." 



Therefore the species has an individuality. It is very similar to the 

 species described here under the name Leidyana erratica. Both are soli- 

 tary, size of the two is nearly the same, ratios of various parts not rad- 

 ically different and shape of the deutomerite quite similar. The cysts are 

 slightly smaller tlian in the latter species, but they dehisce by approxi- 

 mately the same number of spore ducts and the spores are similar. The 

 epimerites of the two species are spherical and large. The nuclei are 

 spherical. The only difference seems to be in the shape of the protome- 

 rite. In all the hundreds of specimens I have seen of L. erratica, none 

 has possessed a protomerite rounded at the anterior end ; all have been 

 decidedly conical at the apex. In the present species, the protomerite is 

 broadl}^ rounded — subspherieal — in shape ; the constriction at the sep- 

 tum is considerably deeper than in the other species. I have separated 

 the two on the basis of this character alone, deeming it of sufficient im- 

 port to differentiate the species. Both species are parasites of the genus 

 Gryllus, but of different species. The host of the former, Grijllus do- 

 mesticus, flourishes in the old world and is rare in the United States, 

 having formerly been found about old log houses, the former occupants 

 of which undoubtedly introduced it from Europe (Blatchley). The 

 host of Leidyana erratica, Gryllus ahhreviatus, is the common field 

 cricket in the United States. The infection is unlikely to have spread 

 from the one host to tlie other. 



HYALOSPORA ROSCOVIANA Schneider 



For detailed synopsis and discussion of this species, see the chapter 

 on Coleopteran parasites, under the same species name. The host is 

 Petrohius maritimus, but as the genus Petrobius has been described for 

 both Coleoptera and Orthoptera, it is impossible to state finally whether 

 the host was a beetle or an orthopteran, or a thysanuran. 



