Neuroterus (verrucarum) visibilis, new species
agamic form

GALL.—Very minute, elongate-oval, hard but thin-walled cells ; with a slightly elevated, circular apex in center of top surface ; surfaces of galls minutely granular ; each cell attached by a broad area to under surface of leaf, producing a barely evident elevation of upper surface of leaf, but cells not embedded in such a depression of under surface (i. e., an elevation of upper surface) as is usual in the American species of the complex ; cells sparsely hairy with rather long trichomes, this clothing however no heavier than that normal to under surface of leaf ; cells averaging 0.8 mm. in length and 0.4 mm. in diameter. Galls abundant on single leaves.

HOST.—Quercus macrophylla, the largest-leaved white oak of the area.

RANGE.—Guanajuato : San Felipe, 8 NE, 7000' (types). Probably throughout a more central area in Mexico, including the state of Guanajuato.

LIFE HISTORY.—Adults: March 6, 14, 25.

The verrucarum complex has been known previously only from the eastern half of the United States. The present species, and the two that follow, extend the records through the Western Sierra to the southwestern corner of Mexico.

This is the first instance of an exclusively Eastern American group occurring in the Western Sierra of Mexico. The gall of visibilis is, however, hardly different from the seed-like galls of the saltatorius complex (which are known both from the Eastern and the Western United States). None of these Mexican species has the gall embedded in as deep a depression as is common in the American species of the group, and the mode of attachment of this larval cell and the extent of the hairy covering of the gall are, after all, the chief differences between the verrucarum and the saltatorius complexes. Since the insects of the two groups differ in very few respects, it is not unlikely that these Mexican species will provide connecting links between them.