496 The American Naturalist. [May, 
vulgaris), and the Hedge Mustard (Sisymbrium officinale); the maggots 
infesting onions, beans, and raspberry canes are different insects, dis- 
tinct from each other and from the Cabbage Root Maggot.” 
The presence of the pest, where it occurs in considerable numbers, is 
indicated by a checking of the growth of the plant, a tendency to wilt 
badly under a hot sun, and a sickly bluish cast to the foliage. .The 
- way in which the roots are injured is shown in the upper figure of the 
accompanying plate. 
Mr. Slingerland discusses the life history of this and allied species, 
and treats of the methods of preventing its injuries at considerable 
length, concluding with an elaborate bibliography and synonymy. 
The bulletin is illustrated by eighteen excellent figures two of which 
we are permitted to reproduce herewith. 
Ohio Dragonflies.—Prof. D. S. Kellicott publishes a valuable 
Catalogue of the Odonata of Ohio’, in which 68 species are recorded 
for the Central and Northern parts of theState. He thinks the num- 
ber of species found compares favorably with other Mississippi Valley 
regions of similar latitude. While lakes, ponds and morasses which 
are favorable homes for the nymphs of the Odonata are not numerous, 
many and copious streams traverse the State, and the great Ohio, the 
Beautiful River, on the south, and Lake Erie on the north, with its 
numerous estuaries and sheltered areas of reed-grown waters, compen- 
sate for the unfavorable conditions of the State at large. Whether or 
not the number of species is decreasing as a consequence of the pro- 
found changes due to more complete occupation of the country by 
civilized man, it is impossible to know. In all probability, the drain- 
ing of swamps and ponds, the resulting disappearance, in Summer, of 
former perennial streams, and the contamination of others, will, sooner 
or later, produce a material reduction. 
“ The common names of the adults are often as striking as the forms 
themselves. In the central and southern sections they are almost uni- 
versally known as ‘snake-feeders;’ in the north and northwest, as 
‘spindles; in the northeast they are often ‘ devil’s darning-needles.’ 
Still, any one of these, and others, may be heard in any section. 
Among the less common designations may be mentioned the follow- 
ing: ‘horse stingers,’ ‘ mosquito hawks,’ and ‘ dragonflies.” The last, 
used more or less everywhere, is, by far, the most desirable. It ex- 
presses so aptly and happily the characteristics of these veritable 
dragons of the air. No insects y 
? Journal Cincinnati Soc. Nat. Hist., Jan., 1895. 
¥ 
