ON A COLLECTION OF THYSANOPTERA FROM PORTO RICO I51 



strong. Abdomen elongate-elliptical, evenly convex above, lateral mar- 

 gins eaves-like ; ninth segment in the female received within the eighth ; 

 tenth segment cylindrical ; bristles on segments 9 and 1 long and strong, 

 all other bristles minute. 



Type : Dinurothrips hookeri Hood. 



A very distinct genus, suggesting Parthenothrips Uzel in general 

 appearance, though approaching Panchcetothrips Bagnall much more 

 closely in eJl important detciils of structure. Both of these genera have 

 wings strikingly different from Dinurothrips. Parthenothrips differs also 

 in the form of the last abdominal segment and in the number of antennal 

 segments ; Panchatothrips has 3-segmented maxillary palpi. The thin, 

 shelf-like margin of the anterior half of the prothorax appears to be a 

 structure unique for the entire order. 



Dinurothrips hookeri, new species (PI. V, figs. 1-4). 



Female. — Length about 1.7 mm. Dorsal surface deeply reticulate. 

 General color dark orange-brown to blackish browTi ; sides of head and 

 thorax, and bases of abdominal segments 3-7 often darker ; abdomen 

 pale toward apex, last two segments heavily chitinized and darkened with 

 blackish ; tibiae, tarsi, and antennal segments 1 , 3, 4, and 5 yellow. 



Head nearly 1 .2 times as wide as long, distinctly longer than protho- 

 raix, very slightly broadest across eyes; cheeks swollen behind eyes, 

 abruptly constricted at extreme base, the dorsal and lateral surfaces of the 

 head anterior to this constriction with a prominent dark carina. Eyes 

 equal in length to their distance from posterior margin of head and two- 

 thirds as wide as their interval, strongly protruding, non-setose. Ocelli 

 approximate, anterior ocellus on a line with the front of eyes, posterior 

 ocelli opposite their centers. Antennae 2.2 times as long as head, with 

 faint chitinous rings ; segment 1 subcylindrical, slightly broader than long ; 

 2 broadest in entire antenna, subspherical, pedicellate ; 3 longest in entire 

 antenna, slender, vase-like in form, pedicellate, abruptly narrowed in api- 

 cal sixth ; 4 shorter and stouter than 3, vase-like, about two and one-hcJf 

 times as long as wide, twice as broad across middle as at ends ; 5 clavate, 

 shorter and about as stout as 4 ; 6 and 7 together (exclusive of the pedi- 

 cel of 6) of same form as 5, but inverted ; 7 about one-third as long as 

 6 ; 8 needle-like in form, longer than 6, terminating in a long hair ; seg- 

 ments 2, 6, 7, and 8 blackish brown, 2 paler apically and with pedicel 

 yellow ; 3-5 clear pale yellow, or 5 slightly infuscate apically. 



