D. Keilin 
400 
Adding the new species to the foregoing, the following table shows 
the chief characters of these three species: 
Sporont 
Leidyana erratica 
.sohtary 
Leidyana gryllorum 
solitary 
Leidyana tinei 
solitary 
Maximum length 
of Sporont 
500/r 
-120/* 
300 y 
Maximum length 
of Protomerit . 
80 y. 
84/* 
40/* 
Shape of Proto- 
merit 
conical 
subspherical 
subspherical 
Cysts diameter . 
320 y 
190-240/* 
90-110/* 
Dehiscence . 
sporoduct 
sporoduct 
sporoduct 
Number of sporo- 
ducts 
1-12 
3-8 
2-5 
Length of sporo- 
duct . 
very long (1200,u,) 
? 
short (40/*-50/*) 
Spores . 
barrel-shaped 
barrel-shaped 
barrel-shaped 
Length of spores 
3-6 y 
ly 
7/* 
Host 
Ortlio'ptera: 
Orthoptera: 
Lepidoptera: 
Geographical dis¬ 
tribution . 
Grylhis pennsylvanicus 
,, abbreviatus 
America 
Gr. domesticus 
Europe and America 
Tineid larvae 
Europe 
According to the lists of the known gregarines wdth their hosts which 
we owe to Minchin (1903) and Watson (1916), the gregarines are very 
common in the larvae and imagines of Coleoptera (about 100 species of 
Cephaline gregarines are quoted by Watson), they occur very often in 
the Orthoptera (35 species) and Neuroptera (20 species). A few gregarines 
have been described from Diptera, Hemiptera and Thysanura, and no 
gregarines have been found in the two large orders of holometabolic 
insects: Lepidoptera and Hymenoptera. The species Leidyana tinei here 
described is the first gregarine recorded as parasitic in Lepidoptera. 
The fact that gregarines have not been previously recorded in these 
two orders cannot be considered as due to lack of observation, since 
large numbers of these Insects have been dissected for many different 
pirrposes. Possibly we can account for the infrequency of their occurrence 
because of the habits of the larvae of Lepidoptera and Hymenoptera. 
These are often parasites in other Arthropods (Hymenoptera) or they are 
gallicolous (Hymenoptera) or phytophagous (Lepidoptera and Hymen¬ 
optera) or they live in nests and cells (Hymenoptera). It is interesting 
to notice that only one of the Coccidia {Adelea mesnili Perez) has been 
described from Lepidoptera and it was found in the larvae of a Tineid 
{Tinea hiseliella ZIL). 
On the other hand the Microsporidia are often found in the Lepidoptera 
and Hymenoptera. 
