34 GEO. H. HORN, M. D. 



Tetracha Carolina, Linn. 



Color yellowish white, head and thorax corneous with metallic 

 surface, the margin of the latter testaceous. 



Form rather, slender, cylindrical, slightly flattened, head and 

 thorax at right angles to the body, last four segments of abdomen 

 gradually arcuate forward. Length .68 inch; 17 mm. Plate II, 

 fig. -3, 3 a to 3 e. 



Head corneous, with geneous surface lustre, general form triangular 

 with rounded angles. Above slightly concave, a strongly elevated 

 transverse ridge posteriorly. Frontal margin with prominent median 

 lobe, lateral lobes feebly arcuate and with a small tooth near the 

 middle lobe; sides in front of eyes rather deeply sinuate, behind the 

 eyes very suddenly narrowed. Head beneath broadly cordiform, very 

 convex, sides subparallel for a short distance at middle, median line 

 (especially in front), distinctly impressed, posteriorly distinctly notched. 

 Apical margin trilobed, median lobe more prominent, Avith convergent 

 sides and oval at tip, lateral lobes triangular, limited behind by an 

 elevated line. 



Eyes. — There are two pairs of eyes on each side of the head. 

 The superior eyes are large and prominent and equal in size, the 

 one near the posterior angle of the head, the other a short distance 

 in front. The smaller eyes are situated as follows : one moderately 

 convex on the declivity in front of and beneath the upper front eye, 

 the second is less convex is on the under side of the head immedi- 

 ately beneath the front large eye. These eyes are so arranged as to 

 admit of a complete circle of vision. In the natural position of the 

 head the posterior eyes look directly backwards, the front eyes directly 

 upwards, the smaller front eye has vision to the front while the other 

 small eye has a lateral scope. 



Antenn.id. — These are situated at the side of the head immedi- 

 ately behind the base of the mandibles, four jointed, first joint stout, 

 setigorous in front, second joint as long as the next two together, 

 flattened and setigerous in front, third and fourth joints much more 

 slender than the others, the terminal shorter than the third. 



Mandibles slender, falciform, acute, more prominent than the 

 margin of the front, armed with an acute tooth near the base. 



MaxillvE stout, with the usual small triangular basal piece, second 

 joint (cardinal piece), attaining the margin of the head, with two 

 small tubercles bearing short spines on the anterior margin near the 

 base, third piece (maxilla proper), stout with a more slender piece 



