l' {Tin; ‘ - l
   
  30 Bulletin N0.·i159  · . ‘
  distal tufts of long diverging setae arise from prominences ,
  ta._. ;_’a near the posterior margin of the posterior body segment. r {
  _ Behind thetufts at the posterior margin of the segment are _. . E
·   _’ two additional setm. Respiratory appendages three—jointed, ` 1
l ‘   v i tapering. Length of body 5.5 mm.   E
  l - No. 3. Orthocladius sp.eThis larva resembles the two , t
  ‘_>p _ jf V preceding in a general way and was taken in some numbers __
  I about rocks in Straight Creek near -a dwelling occupied by  ; S
  people affected with pellagra. Cylindrical, elongate, plainly . 3
  segmented. Head yellowish brown, posterior margin at _‘ li
  sides definitely black. Jaws black `at tips, curved, acute, i t
  three sharp denticles within apex, then a strong process from ` O
  which springs a very finely denticulate plate expanding to-  f S
  ward the base of the jaw. Mentum black at lateral margin,  ? 0
  brown medially; four lateral teeth large, acute, black, tooth  ·
  , next within smaller, brownish; the next obliquely truncate } C
  and brown; median broad; plate-like, brown. Antennae on i . S
  :_’ Q A small prominences, less than one—fourth the length of the ` d
  head; first segment longest, bearingiat its distal extremity  A 3
  two acute appendages, one nearly .as long as all the remain- i  t,
  ` ing segments, the second not quitetwo—thirds as long;  _ V
  second segment a little more than one third the length of r
  H the first. Black specks on side of head not quite contiguous,   S.
  the anterior much smaller and lunate. Claws of the false  i » t.
  legs of the first body division strongly curved, many of them J  
  toothed. Tufts of hairs at posterior extremity on small  _ D
  prominences. Respiratory appendages not jointed, the  § it
 . i ·dorsal pair longer and club-shaped. Lengtha,4.5 mm. The   S C
  broad truncate median tooth of the mentum is suggestive   t-
 “ of the genus Thalassomya, as described by authors. , _ b
  No. 4 Ablabesmyia sp..——A single dipterous larva   A
  found at Cary in the Left Fork of Straight Creek is very  Q K 3
  different from all the above in a number of features. The   ` tl
 L  body is rather short and stout, about 4.5 mm. long; the head  - 1;
   g relatively large, elongate and fiat, with one black speck on I tj
  each side, with an anterior fissure. Antennae with the long  i e
  first segment largely concealed by an extension of the crust.  _' vi
  Hooks of anterior prolegs retractile. Each body division   C
   ‘ r  i
»$,···;  , .