162 
siticworin: "It makes no swelling or deformity, as do many other 
Anguillulids, but causes a brown patch on the leaves.*' I have not 
before met a more ample description of this species. 
I avail myself of the opportunity kindly offered to me to recommend 
to the attention of the members of the Association of Economic En- 
tomologists a treatise of my hand, inserted in the recently published 
second number of the "Zeitschriffc fur Pnanzenkrankheiten,'' edited 
by Prof. Sorauer (vol. in, p. 69), a copy of which I took the liberty to 
send annexed to the secretary of the Association. In this treatise I 
describe a new species of Aphelenchus, which causes a disease in the 
leaves of Begonia and those of Asplenium bulbiferum and A. diversi- 
folium, and which produces no hypertrophy or galhfication, as do 
indeed all other nematoid worms living parasitically in plants, as far as 
I know them, but makes the affected parts die away immediately with- 
out any preceding deformity. My new nematoid worm causing the 
death of the tissues, I named it Aphelmchus olesistus (6X — eo, radical of 
6Uv';ai=to destroy; (tfr<;c= tissue). 
Eor a minuter discription of the species I beg to refer to my treatise 
in the "Zeitschrift fur Pnanzenkrankheiten v (in, p. 75-78). Still, I 
permit myself to state concisely the characteristics which distinguish 
my new species of Aphelenchus from the other well-known species of this 
genus. I have indeed some surmise that my new species is identical 
with the species meant by Prof. Atkinson in the above-mentioned 
information. 
Firstly, I build my conjecture on the fact that both cause the decay 
of the parts of plants in which they live without causing gallification 
or hypertrophy as preceding symptoms, the more so, because all other 
kinds of Xematoids living parasitically in plants, as far as is known r 
give rise to the said deformity, and only after that, having strongly 
multiplied in the tissues, cause the death of the cells. 
Secondly, I observe that the Aphelenchus of Prof. Atkinson, as well 
as mine, can live in very unlike species of plants, but that both were 
till now discovered in pot plants only. 
In order to contribute to a decision, if possible, whether the Aphe- 
lenchus of Prof. Atkinson be or be not identical with my Aphelenchus 
olesistus, I give here a very concise description of the latter. 
Deserijition. — Length of the males, varying between 0.51 and 0.62 mm. (average,. 
0.58 mm.); that of the females, varying between 0.55 and 0.81 mm. (average, 0.68 
mm.). 
The proportion of the length to the greatest breadth of the body lies between £ f 
and \K 
The proportion of the length of the body to that of the oesophagus ranges between 
Jf andf. 
The spear is very delicate and small, becoming thicker to the back part and with- 
out ending in a knob. 
The vulva lies at about one-third of the length of the body from the hindmost 
extremity of the body. The ovaria are double ; one of them is found before, the other 
behind the vulva ; the latter ovary is the shorter of the two. 
Spicula of the male slightly bent, length. 0.009 mm . ; accessory part very small. 
