190 SUMMAEY OF CUERENT RESEARCHES RELATING TO 



Studies in Mecoptera.* — R. J. Tillyard has made an interesting 

 study of a new family, Nannochoristidse, in the ancient order of 

 Mecoptera, or Scorpion-flies. The Nannochoristidae are minute insects, 

 represented by four new Australian species of the new genus Nanno- 

 chorista, which is " an example of a highly specialized reduced type 

 based upon a very archaic foundation," and by an allied New Zealand 

 new genus, Choristella, with one species. The archaic characters of 

 Nannochorista include the high roof-like manner of folding the wings, 

 and the presence of a wing-coupling apparatus, with frenulum well 

 developed. The coenogenetic characters include the reduction of size, 

 the loss of macrotrichia from the wing-membrane, the reduction of 

 the sub-costal vein, the loss of the first apical fork, the high specializa- 

 tion of the mouth-parts. To students of Panorpoid orders the new 

 type will be of great interest. The male closes his anal forceps on the 

 tip of the abdomen of the female in a lock-grip. The New Zealand 

 type has a wing-venation even more reduced than in Nannochorista. 

 The distribution of this highly-specialized family derived from a very 

 ancient stock (in Tasmania, the Eastern Highlands of Australia, and 

 New Zealand) can only be explained by dispersal from an original 

 common Antarctic ancestor. 



Protocerebrum of Micropteryx.t — P. A. Buxton has made a 

 thorough study of the protocerebrum of Micropteryx {Eriocephala) 

 caUhella, the smallest insect of which the brain has been investigated in 

 any detail. Most entomologists regard Micropteryx as a primitive 

 Lepidopteron ; there is good ground for regarding it as a Trichopteron. 

 Chapman has raised it to ordinal rank (Zeugoptera). 



The neurilemma, which covers the whole of the central nervous 

 system in one continuous sheath, is a thin syncytium. Beneath it 

 are found the ganglion-cells and the asonic parts of the nervous 

 system. Over the protocerebrum the layer of ganglion-cells is deep, 

 and four types can be distinguished : the normal type, the mushroom- 

 body cells, the cells of the optic lobes, and the giant cells. Neuroglia 

 cells are found in the substance of the protocerebrum in small numbers, 

 and the tracheal system of the brain is very slightly developed. The 

 protocerebral lobes exceed in bulk the rest of the protocerebrum. A 

 mid-dorsal protocerebral lobe is specially described as the tumnlus. 

 The mushroom-bodies are small and simple, with a spherical head 

 which contains minute glomerular masses of nerve-fibres regarded as 

 association-centres. An account is given of the stem of the body and 

 its division into three roots (inner, forward, and backward). The central 

 body is large, and consists of an outer and an inner capsule, the latter 

 containing a number of minute glomerular bodies. The tracts passing 

 from or to the central body are numerous, and some of them are 

 large. The nerves from the ocelli run inwards across the front of the 

 head of the mushroom-body and pass gradually into the substance of 

 the protocerebral lobes, and a few fibres pass into the bridge. Two 

 small bodies beneath the central body are probably the ocellary glomeruli 



* Proc. Linn. Soc. N.S.W.. xlii. (1917) pp. 284-301 (2 pis. and 3 figs.). 

 t Trans. Entomol. Soc. London, 1917, pp. 112-53 (4 pis. and 3 figs.). 



