930 CHARLES PAUL ALEXANDER 



Dr. Adam Boving found this species in Iceland and made careful notes 

 on the burrows made by the larvae. Thru the kindness of Dr. Boving, 

 the writer is able to include a translation of his manuscript. The writer 

 is indebted also to Dr. Lundbeck, director of the museum at Copenhagen, 

 for the loan of this material for study. These are the specimens discussed 

 later in this paper. Boving' s notes were made at Fell Station, southeast 

 Iceland, in 1908. The translation follows: 



Inside the moraine of 1877, in the low hnd where ice was standing in 1886, quantities of 

 dipterous larvae were found in the moist sand on the bottom of flat hollows which at times 

 are flooded by water and at times are partly drained, as was the case on the day when the 

 following observations were taken. 



The whole dark, moist surface of the bottom was covered by an irregular system of slightly 

 elevated, long, tubular galleries, some of which were rather straight, some formed broken 

 lines, some peculiar arabesques, and some plain spirals. The width of the galleries was about 

 the size of an ordinary pinhead, some a trifle larger, some a little smaller. In the anterior 

 part of each gallery was found either a cylindrical white tipulid larva (Helobia) about one 

 centimeter long, or another dipterous larva of the same general size and appearance. The 

 larvae were found just below the surface. It was not always easy to capture them, for when 

 I pushed my knife under -the mouth of the gallery they moved quickly backward, and then, 

 digging deeper into the soil, made a new gallery that branched off from the main one. It 

 was not possible to distinguish the galleries of the crane-fly larvae from those of the other 

 dipterous associate. Very often, from the mouth of the spiral galleries, one-third of a 

 broken pupal skin stuck out; but larvae were found also in many of these galleries. 



The imagines of the two Diptera were present in large numbers, some flying close to the 

 ground, others resting on it. Both forms were long-legged and capable of running over 

 the water film. I secured a pair of both in copulation. The eggs were found on the moist 

 surface, singly or in small masses of two or three together. 



' The larvae feed, of course, on organic particles in the sand. The imagines were not observed 

 to take any nourishment at all; they copulated as soon as they had left the pupal skins, and 

 I did not find them in any other place than on the bare, moist soil where the larvae lived; 

 not, for instance, on flowers growing near by. 



A small carabid (probably Bembidion grapii Gyll.) was present in the locality in com- 

 paratively large numbers, evidently preying on the larvae of the Diptera. A single cara- 

 bid larva also was found; from its size and habitus it may very well be the larva of the 

 Bembidion. 



A small black spider was probably feeding on the imagines of the Diptera. It did not make 

 a regular web, but spun a number of single threads, each about two feet long, attaching them 

 to a piece of gravel and proceeding from this as a common center, spreading the threads 

 close to the ground like radii, and finally fastening the ends to small grams of sand. 



The adult flies of Helobia hybrida are very common. They are the 

 first tipulids to appear on the wing in spring, some appearing in early 

 March or, in open winters, even in late February. They remain until 

 late in the fall. The writer has noted the females running about on the 

 wet sand along the banks of the Kaw River at Lawrence, Kansas, and 

 ovipositing quite as described by Hart (1898 [1895]: 199-200). 



Larva. Length, 7.8-10 mm. 



Diameter, 0.6-0.7 mm. 



