140 



THE BRITISH NATURALIST. 



[June 



genus under inspection, but I found the antennae were fixed and not 

 protrusile and movable, as in T any pus. 



The two uppar mandibles (one of which is shown in the enlarged 

 drawing at x), work on a kind of pivot, but both meet for tearing 

 purposes on the hard, chitinous lower jaw, thus making a tripod. They 

 work, in fact, in planes at right angles to each other, their line of inter- 

 section being the axis of the head or lower jaw. 



Larva, Fig. 3, h\, was found in the ponds on the golf links at St. Anne's- 

 on-the-Sea, and is not unlike C. dovsalis, except in the antennas a, and 

 in the shape of the eyes. The nerve ganglia was seen on each side, and 

 the secretion glands for making its tube-like dwelling amongst the mud 

 or roots of water plants can be seen behind the pharynx ; also notice 

 anal segment b with pro-legs and branchial anal plates, &c. 



My friend, Mr. Hammond, F.L.S., discovered Species Fig. 3, hi. which 

 I call Chironomus potamogetus, because it is always found mining tunnels 

 in the floating leaves of Potamogaton (y). 



The larva has 14 segments in the body including the very protrusile 

 retractile head and anal segment very like Fig. 3, ii. b. . The anterior 

 pro-legs are remarkable for the curious minute hooklets with which the 

 skin below the exterior larger hooks of the sucker-foot are covered (Fig. 

 3, hi., a and $). They looklike the projections on the proboscis of some 

 of the Nereis annelids or that of the Gephyrean worm Sipunculus. The 

 posterior feet are not ornamented like the fore feet, but are longer and 

 more protrusile. 



Most singular of all is the curious action of the mandibles and their 

 position, so differing from Fig. 3, i., which meet on the horny plate 

 below the mouth. 



These mandibles work in an upright way, seeming to retract for the 

 straight down stroke. As Mr. Hammond says, " they work in longi- 

 tudinal-vertical and parallel planes, like the hooklets of the maggot of 

 the blow-fly." You will see that the head is much narrowed to allow of 

 more freedom of movement in the close quarters in which it resides. 



(To be continued.) 



NOTES ON EARLY MAN: THE PLIOCENE PERIOD. 



BY JOSEPH SMITH, F.R.S.A., M.R.I. A. 



(Continued from page 116.) 



■ 



The remains of Quaternary man have been found in as many as forty 

 localities in the western part of Europe, and these excavations have 

 rescued to science no less than forty skulls in such stages of preservation 

 as to render them valuable in ascertaining the physical condition of man 



