386 



NEUROPTERA 



undetermined species called by the officers and crew of her 

 Majesty's ship Penguin the " compass ant." The outline of one 

 of the structures formed by this Termite we represent in Fig. 239. 

 Mr. J. J. "Walker, to whom we are indebted for the sketch from 

 which this figure is taken, has also favoured us with the following 

 extract from his diary, of date 4th August 1890 : " The most in- 

 teresting feature in the scenery (about forty miles inland from Port 

 Darwin) was the constant succession of huge mounds raised by 

 the Termites, of which I had seen some comparatively small 

 examples in my rambles near Port Darwin ; but these exceeded 

 in dimensions all I had ever seen. The most frequent as well as 

 the largest kind was usually of a reddish or ferruginous colour 

 outside, and generally almost cylindrical in shape with obtusely- 

 pointed top, but nearly always more or less weather-worn, with 

 great irregular buttresses and deep ruts down the sides ; many of 

 them look like ruined towers in miniature. Their usual height 

 was from 8 to 10 feet, but many were much higher, and some 

 attained an (estimated) elevation of at least 20 feet. Another 

 kind, .seen only in one or two places along the line, was of a much 

 more singular character ; they averaged only 4 to 5 feet high, 



were built of a dark -gray mud, 

 and in shape were like thin flat 

 wedges set upright (see Fig. 239), 

 reminding one of tombstones in 

 a churchyard. But the most 

 remarkable feature about these 

 mounds was that they had all 

 the same orientation, viz. with 

 the long faces of the wedge 

 pointing nearly north and south. 

 Why this is so I am quite at a 



^^mdlkJA 



FiQ. 239. — Termitarium of compass or meri- 

 dian Termite of North Australia. A, 



face e.xteudiug south and north ; B, cross- losS to imagine, and I much re 

 section. ° 



gret that I had no opportunity 

 of closely examining these most singular structures. A third 

 kind of mound, usually not exceeding 2 feet in height, was of a 

 simple, acute, conical figure, and generally of a gray colour some- 

 what paler than the last." 



The material used for the construction of the dwellings is 

 either earth, wood, or the excrement of the Termites. The huge 

 edifices mentioned by Smeathman are composed of earth cemented 



