8 BULLETIN 1098, U. S. DEPARTMENT OF AGRICULTURE. 
These records indicate general breeding of Anopheles through- 
out the course of the stream under natural conditions. Anopheles 
quadrimaculatus Say is the common species taken, and Anopheles 
punctipennis Say is second in numbers. It is noted that one collec- 
tion of Anopheles crucians Wied. was made. The undetermined col- 
lections represent the Anopheles larve which were collected but 
which were not reared to the adult stage. 
For convenience of the survey, the section of the bayou to be 
cleared of all vegetation was divided into stations 100 yards in 
length. The distance covered in the experiment was 1,600 yards, 
nearly a mile. The plants collected from this section, before clear- 
ing, during July and August, 1915, are shown in Table 2. The plants 
listed in Table 2 are distributed according to their location and the 
depth of water in the bayou in Table 3. The plant determinations 
were made by the Bureau of Plant Industry of this department. 
The natural conditions in the bayou, including the vegetation, water 
levels, and other features, are shown in Plate III, Figure 3; Plate 
IV; and Plate V, Figure 1. 
TABLE 2.—Plants from Bayou Walnut, Mound, La., 1915. 
Species. Common name. Location. 
SpITOSyTAISD so oeek sae eerie cn crenee ete eee Agee Soo ate ce Se at ae Submerged. 
Lemna valdiviana, Lemna gibba, Spirodela 
polyrhiza, and Wolffia columbiana-..........-. Duckweedines-se-- ase. Floating on water. 
SUISSE; CLETUS Aye eee te oe ne Primrose-willow - -..-. In waiter, roots in bed. 
ZIZADLODSISHMUMA CEA pee eet hearers eo eee Aquatic eTaSS=e-..22 22 Oo. 
Cephalanthus occidentalis....................... ‘Buttonbushes. "= 222 In channel and along margin. 
SALER/ MIST O aie remeeea ny noe BRE pl el yuna pee eL Ia a Swamp willow........ Along margin, overhanging. 
IDISNONIA TACICAMSo nee eat eee ee ere che Trumpet creeper ..: =. Do. 
BTN NI ChIAGirrnOSae le ee = eee eee ere re Buckwheat vine. ..... Do. 
IPCLSICATIA}OPElOUSATI As ese see eee ee eee SMariweedeeces seen se Along margin. 
Phy Gola cca aim Chi Camcae per meee ae ee ee ee Pokeberry, S502 5 a Do. 
PaniCuIMyCOlLOnirny aes fe eee ere Ditch erass=seeee eee Do. 
FASCLOPIAS DP CREMIMIS ae cele eo ete eres early oe Milkweed. 2: 22.2 ....52 Do. 
AMP CLOPSIS ALD ONeAe ce tee eee ee eee eee Peppenvines- sess sees Do. 
Belonging tofamily Euphorbiaceae........... .. SPULLelsekeeaee see oe Do. 
TABLE 3.—Vegetation and depth of water in Bayou Walnut, Mound, La., before 
impounding, July-August, 1915. 
Vegetation. 
Sta- Depth of water 
tion. in channel. 
Species. Common name. Location. 
| (MEM ASD DL: se see ce ae Duck weeds a2 2 eee Floating on water....... 
Jussiaea diffusa... ......| Primrose-willow........- WS ber 3.5 SoMa eet 
Cephalanthus occiden- | Buttonbush...........-- Bed and margin......... : 
er talis.. ; 6 inches to 11 
Magee || eps I Biper aha ze I ee Se ln Swamp willow.........- Margin, overhanging....|{ inches. 
Persicaria opelousana....) Smartweed.............. Marpin: bs Se cence tacts 
Zizaniopsis miliacea..- .. AQUATIC 2TaSSS es secs Bed, in water. c.c... 222 
Fuphorbiaceae........-- Spurge eee he eee Margin’: seccrcerac ue 
1 The species of duckweed recorded under Lemna spp. in this list represent Lemna valdiviana, L. gibba, 
Spirodela polyrhiza,and Wolffiacolumbiana. Submerged alge (Spirogyra) were common along the margins 
in some locations, but the submerged hornwort (Ceratophyllum wae not collected in this survey, though 
it is common in some other locations in the region. 
