CTJLEX ELEVATOR 415 



Taken by the junior author in a pool of clear water containing Tegetable debris at 

 the head of a small stream two miles west of Port Limon, Costa Rica. The adults 

 were not bred. 



The following is an abstract of the table : 



1. Antennse with the tuft outwardly placed, the part beyond slender . 5 

 5. Air tube four times as long as wide or over 7 



7. Anal appendages four, normal 8 



8. Air tube with four to ten paired tufts along the posterior line in a 



straight row, none displaced, or the hairs obsolete or absent 18 



18. Air tube without a crown of spikes, smooth throughout 19 



19. Air tube with long well-defined tufts 20 



20. Body spicular-pilose 21 



21. Five tufts on tube with the basal one very long, the rest progress- 



ively shorter; abdominal hairs in threes on segments 3 to 5. 23 



23. Upper head hair single; tufts of tube all shorter than half its 



length 24 



24. Pecten sparse and open, equalling the diameter of the tube at 



middle elevator 



Obiqiitai, Desceiption op Cttlex edtjcator: 



Antennae with the tuft at outer third, dark; head hairs single; body coarsely hairy; 

 lateral hairs in twos on the second segment, in three on the third to sixth; sub- 

 dorsal hairs long, stellate; tracheae narrow. Air tube 6 X 1, a little tapered, pecten 

 moderate; five tufts on the posterior margin decreasing to tip. 



Collected by the junior author in an old stream bed disconnected from the stream, 

 containing fish, but the larvae in reeds at the edge, Rio Aranjuez, near Puntarenas, 

 Costa Rica. The adults were named " Melanoconion atratus Theob." by Mr. 

 Coquillett. 



The following is an abstract of the table : 



1. Antennae with the tuft outwardly placed, the part beyond slender. 5 

 5. Air tube four times as long as wide or over 7 



7. Anal appendages four, normal 8 



8. Air tube with four to ten paired tufts along the posterior line in a 



straight row, none displaced, or hairs obsolete or absent 18 



18. Air tube without a crown of spikes, smooth throughout 19 



19. Air tube with long, well-defined tufts 20 



20. Body spicular-pilose 21 



21. Five tufts on tube with the basal one very long, the rest progress- 



ively shorter; abdominal hairs in threes on segments 3 to 5. 23 



23. Upper head hair single; tufts of tube all shorter than half its 



length 24 



24. Pecten of tube dense and fine, not as long as diameter of tube 25 



25. Dorsal hairs stellate, long; antennae dark educator 



Desceiption op Femaub, Male, and Labva op Cttlex elevatoe: 



Female. — Proboscis rather long, swollen at tip, labellae conically tapered; 

 vestiture black with a slight bronzy reflection ; setae minute curved, black, those 

 on labellae more prominently outstanding. Palpi short, one-fifth as long as 

 proboscis, slender, black, with a few outstanding setae at base. Antennae moder- 

 ate, joints subequal, nigose, coarsely pilose, black, second joint not much longer 

 than third; tori subspherical, with a cup-shaped apical excavation, yellowish, 

 brown on inner side ; hairs of whorls sparse, moderate, black. Clypeus rounded 

 triangular, convex, brown, nude.' Eyes black. Occiput brown, clothed with 

 broad, flat bronzy-brown scales with a gray luster in some lights and many erect, 

 forked black ones, a patch of flat white scales low down on the side, a row of 

 bristles along margins of eyes. 



Prothoraeic lobes elliptical, remote dorsally, clothed with pale scales and black 

 setae. Mesonotum dark brown, clothed with narrow, curved, light bronzy-brown 

 scales and with rows of coarse black bristles. SeuteUum trilobate, with similar 

 vestiture to mesonotum, each lobe with a group of black bristles. Postnotum 

 elliptical, prominent, dark brown, nude. Pleurae and coxae dark greenish, with 

 rows of brown bristles. 



