122 
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arated from each other a distance about equal to the length of a spinule, 
the distance between the spinules in a row being approximately half as 
great. ‘The number of spinules is from twenty-one to twenty-five in 
each row. 
L. hirticula and rugosa (Plate XIL., Fig. 2 and 3).—In this group 
the median rows of mucronate spinules are much more prominent than 
in the preceding, the bases of the spinules being decidedly thicker than 
the hairs adjacent, and the spinules placed much more closely in a row 
(almost in contact), the rows being decidedly shorter—about half the 
length of the ventral surface of the segment—and stopping short of 
the anal slit. The rows are also further apart—a distance about twice 
the length of a spinule. The hooked hairs are fewer and more sparsely 
placed. Spinules about twenty-nine in a row. 
L. gibbosa (Plate XII., Fig. 7).—A much smaller larya than the 
preceding, characterized by a still greater shortening of the median ave- 
nue through’ an approximation of the hairs and a lateral thickening of 
their bases, these now becoming at least twice the diameter of the hairs 
adjacent. Tips of the spinules strongly inclined, nearly meeting in the 
middle, spinules of each row contiguous. The rows approximate at the 
ends, and extend about one third the length of the ventral surface of 
the segment. Patch of hooked hairs much reduced in size, not reaching 
ends of anal slit, but extending farther forward than the ends of the 
rows of spinules. 
LIST OF ILLINOIS SPECIES OF LACHNOSTERNA. 
There are thirty-two species of white grubs belonging to the genus 
Lachnosterna credited to Llinois by the collection of the adults, twen- 
ty-six of which (marked with a star) are in my office collections. The 
habits of the larvee of these species are so far as known practically iden- 
tical, but the greater part of them have of course never as yet been 
bred. separately to the imago. 
L. lanceolata, Say.* Rare, Central and Southern Illinois. 
L. preetermissa, Horn.* Rare, Southern Illinois. 
L. glaberrima, Blanch. Rare, Illinois. 
L. ephilida, Say.* Frequent, Southern Illinois. 
L. longitarsus, Say.* Infrequent, Illinois. 
L. gibbosa, Burm.* Abundant throughout State. 
L. hirtiventris, Horn.* Rare, Central Tlinois. 
L. congrua, Lec.* Infrequent, Illinois. 
L. prunina, Lec.* Rare, Northern Illinois. 
L. crassissima, Blanch.* Infrequent, Central and Southern Illhi- 
L. inversa, Horn.* Abundant throughout State. 
L. bipartita, Horn.* Infrequent, Southern Illinois. 
L. micans, Knoch.* Infrequent, Central and Southern Illinois. 
L. arcuata, Smith.* Rare, Southern Illinois. 
L. dubia, Smith.* Not common, Central and Northern Illinois. 
L. insperata, Smith.* Rare, Northern Illinois. 
L. fusea, Frohl.* Abundant throughout State. 
L. grandis, Smith. Rare, Illinois. 
L. marginalis, Lee.* Rare, Illinois. 
