New Neotropical Thysanoptera Collected by C. B. Williams

The present paper brings forward several new genera and a number of new species collected by Mr. C. B. Williams during his residence in Trinidad from 1916'to 1.919 and also during a short trip to the Lesser Antilles in March and April 1915.It was originally intended by Mr. Williams that the material be worked up by us jointly; but my own delay in getting at the task until he had been appointed to the distant post of Ento- mologist to the Egyptian Ministry of Agriculture has made such co-operative work seem inadvisable.During his various visits o the United States the systematic position of many of the genera and species was worked out by Mr. Williams and ten- tative manuscript names assigned.These names have been retained except in the ease of several of the more interesting and conspicuous forms which, I think, are better named after their collector in recognition of his exceedingly valuable work on this group of insects.The following descriptions are preliminary to other papers in press or in preparation, and are published at this time in order that the worth of this splendid eolleetioneertainly the largest ever brought out of tropical Amerieamay not be lessened by the otherwise inevitable loss of priority in many of the names.The holotypes, allotypes, and a portion of the paratypes have most generously been placed by Mr. Williams in my col- lection.Stomatothrips septenarius sp.nov.Female (maeropterous).Length about 1.4 mm.Color testaeeous, with head, prothorax, two pterothoraeie transverse bands (one near middle and one at base), abdominal segments 3-9, all tibim and tarsi, and antennal segments 4-9, blackish brown; antennal segments 1-3 yellowish white, 4 paler basally; fore wings pale gray-brown, with two white cross bands, one narrow and at basal sixth, the other wider and at apical seventh, 1925] New Neotropical Thysanoptera 49 intermediate brown area somewhat pMer at middle; hind wings light gray with two pale bands corresponding in position with those on fore wings.Maxillary palpi seven-segmented, the basal segment large; labial palpi five-segmented, the basal segment short.Fore wings somewhat expanded apically, broadest at apical sixth, where they are about 1.6 times as wide as at basal fourth.