392 



2. Apical abdominal segment terminating in a pair of long, tapering, 



backwardly directed thorns; first abdominal segment with the 

 postspiraeular hairs as long as head and thorax combined 

 (Spogostylum) .3 



— Apical abdominal segment usually more or less truncated and with 



an upwardly and backwardly directed upper process and one or 

 two smaller protuberances below it; first abdominal segment with 

 the postspiracular hairs much shorter than head and thorax 

 combined 5 



3. Head with 4 long thorns on upper anterior margin, the lower one 



on each side with a small protuberance at base on under side ; the 

 pair of thorns on lower portion of central line of face large, their 

 bases contiguous ; hairs on head and thorax very long ; laterad of 

 the short thorns the transverse armature of dorsal abdominal seg- 

 ments 2-6 consists of 2—3 long, widely placed rounded hairs 



Spogostylum anale. 



— Head with 6 short, stout thorns on upper anterior margin 4 



4. The pair of thorns on lower portion of central line of face small, 



their bases subcontiguous ; hairs of abdomen, except those of 

 verse armature of dorsal abdominal segments 2-6 consists of 12-20 



long, closely placed, flattened hairs 



Spogostyhim simson (p. 393). 



— The pair of thorns on lower portion of central line of face large, 



their bases, subcontiguous ; hairs of abdomen, except those of 

 basal segment, normal Spogostylum albofaseiatum (p. 395). 



5. Antero-lateral margins of head each with 1 strong thorn, upper an- 



terior margin with 2 such thorns, making 4 in all : labnim with a 

 bifid thorn Clirysantlirar fulvoliirta. 



— Antero-lateral margins of head each with 2 strong thorns, upper 



anterior margin Avith 2 such thorns, making 6 in all 6 



6. Labrum with a strong bifid thorn ; wing Avith a median subcostal 



protuberance Aplwebantus mus. 



— Labrum unarmed 7 



7. The stout thorns on dorsal abdominal segments turned up at bases 



and apices 8 



— The stout thorns on dorsal abdominal segments turned up at apices 



only 11 



8. LoAA r er lateral cephalic thorn AA'ith a palp-like organ projecting on 



its under surface at base, the apex of Avhich is armed with several 

 hairs Bombylius. 



— LoAver lateral cephalic thorn AA-ithout a palp-like organ on under sur- 



face 9 



9. Apical 3 segments Avithout the dorsal transA 7 erse series of short 



thorns, armed only with slender hairs ; no slender hairs inter- 

 spersed betAveen the short thorns of median portion of series on 

 other segments Argyramoeba ocdipus. 



