770 CHARLES PAUL ALEXANDER 



R. C. Shannon, on the Potomac River near the mouth of Dead Run, Fair- 

 fax County, Virginia. They were found during the latter part of May, 1916, 

 in a much-decayed maple log, where they were associated with the larvae 

 of the syrphid fly, Temnostoma bombylans (Fabr.) (Barber, 1913). Greene 

 attempted to rear the larvae procured at this time, but did not succeed. 

 In May, 1917, he sent the writer one of the preserved larvae for study. 

 Later Dr. Viereck was interested in the matter, and on May 27 he procured 

 one fine, healthy larva, which was sent to the writer at Ithaca, New York. 

 It arrived safely on the 29th, and was at once placed in rearing. Unfortu- 

 nately this larva died the day after it came into the writer's possession, 

 and this remarkable insect still remains unreared. Associated with this 

 larva in the pieces of decaying maple in which it was shipped, were 

 larvae of Temnostoma and a larva and a pup"a of the tipulid Epiphragma 

 solatrix. 



The evidences that this larva is that of Protoplasa are numerous. 

 It belongs, without doubt, to the Nematocera, and the immature stages 

 of all the remaining families of that division have been made known. 

 Many features in this larva point strongly to the condition in other families 

 of crane-flies. The eucephalous condition of the head, and the elongate 

 breathing tube, are suggestive of the Ptychopteridae; the five-lobed 

 spiracular disk, the anal tracheal gills, the metapneustic respiratory 

 system, and other features, are very similar to conditions in certain 

 Tipulidae. However, there are conditions obtaining here that are found 

 nowhere else in the Diptera, so far as is known to the writer, such as the 

 combination of a eucephalous head of primitive organization, a stout, 

 non-retractile breathing tube, the large, pinnately branched anal gills, 

 the multisetose punctures on the head, and the details of structure of the 

 mouth parts. The multisetose punctures are suggestive of the branched 

 or plumose hairs of Ptychoptera, and give a possible hint of the origin 

 and ancestry of this condition in the latter group. The writer cannot 

 but regard it as suggestive that the larvae are found in direct association 

 with those of Epiphragma in saturated decaying wood. He has mentioned 

 in other papers (Alexander, 1910:254, and 1919 d: 883, 915) the remarkable 

 superficial resemblance that exists between the adult flies of Epiphragma 

 fasdpennis and those of Protoplasa, both forms having very hand- 

 somely banded wings of a pattern not found in other species in the local 

 fauna. 



