306 PROCEEDINGS OF THE 



back a darker tint; and the skin is covered with numerous small 

 black or fuscous-black dots, arranged in rows. In all there are 

 five rows of these dots, arranged as follows: — One row on the 

 centre of the back, the dots composing it being of a nearly 

 uniform size, as well as more numerous ; in the second row 

 the dots are fewer, there being about three to each segment of the 

 body; the following row has two dots to a segment, one large, the 

 other small; the next is composed of one long dot; and the last 

 row is made up of the above-mentioned small marks over the feet. 

 On the second segment the two first dots are of an irregular shape, 

 and larger than any of the others; and a little below and in front 

 of them are two smaller dots. The last segment is clear from 

 marks. The length of the larva is about five lines. 



Tliis is the only gall-making saw-fiy larva that I have seen 

 bearing marks of any kind on the body; all the larvae of the 

 other known species being of a uniform colour. Unfortunately, 

 all my specimens spun up before I could notice whether they 

 changed colour at the last moult or not, I have a very vague 

 remembrance that they then became of a slate colour, like those 

 of N. cinerece; but further observation is necessary to decide 

 this point. 



In their general habits the larvae do not differ from the other 

 species. The cocoon was spun in the earth, or inside the gall 

 itself. It is of the same size as that of N. Vallisnieri, and of a 

 like colour. The majority of the larvae I had spun up by the 

 middle of August; and from these the flies were developed in the 

 following February. 



The puj)a is white. 



The imago may be characterised thus: — 



Nematus herbace.e, sp. n. 



N. niger, nitidis, ore, genuhus late, tibiis, tarsisque sordide testaceis; 



ano, costa, stigmate, tegulisfjue pallid is; alis hyalinis; cercis bre- 

 viuscidis. 



Long. TJ — If lin. v 



Female: Antenna) shorter than the body, moderately stout, 

 with a lens seen to be covered with a close microscopic pile ; two 

 basal joints prominent; the third and fourth joints almost equal 

 in length. Head black, shining; the vertex fiiintly punctured; the 

 frontal sutures distinct; the surface covered with a short pile; 



