54 THE ENTOMOLOGIST. 



easily seen. For this purpose it is an ndviintage that they 

 should be movable, since they could be adjusted to slope down 

 from the sides of the body to the surface on which the insect 

 rests, playing the same part for the metathorax as the hind legs 

 do for the abdomen, and the middle legs for the fore part of the 

 body. It will be noticed that in the new species of Prisopus 

 there is a well-marked triangular process on each side of the 

 metathorax, corresponding in position with the movable ap- 

 pendages of Cotiilosoma ; and as to the meaning of this process 

 there can be very little doubt. 



Apart from the assumption made by Wood-Mason, there is 

 no reason whatever for believing that Cotylosoma is aquatic in 

 its habits. On the contrary, we have very good reason for 

 believing that it is not. Before Wood-Mason wrote his paper, 

 some years even before Murray's paper appeared, MacGillivray 

 described as Prisopus carlotue a species which really belongs to 

 the genus Cotylosoma and which is very closely indeed allied to 

 dipncusticum. Concerning this species he tells us : — " The colour 

 is variable ; it is either a dull greyish- green, finely and irregu- 

 larly mottled, or silvery-grey, also mottled, having greenish and 

 yellowish shades, altogether reminding me of some of the 

 lichens.*' Very unusual colours for an aquatic insect, but by no 

 means exceptional in an insect which "is said," as MacGillivray 

 further states, ** to be found on the trunks of trees." 



Prisopus JisJtcri, n. sp. 



Colour : on the exposed parts of the head, thorax, femora, and 

 tibite light yellowish brown, with a more or less considerable ad- 

 mixture of ashy white and greenish white ; on the elytra, dark green 

 at the base and over the basal prominences, dark brown beneath 

 these on each side, yellowish brown, varied with greenish grey over 

 the rest of the surface, but becoming darker towards the apex, and 

 with two dark brown spots on each elytron a little past the middle ; 

 pale grey on the upper surface of the anterior segments of the abdo- 

 men, dark brown on the posterior segments ; exposed parts of the 

 under wings coloured like the posterior half of the elytra, the folded 

 parts pale green, mottled irregularly with dark brown ; body beneath 

 chocolate-brown on the abdomen, pale testaceous on thorax, with 

 blackish hind border to the meso- and meta-sternum. 



Head without spines, but with four short rows of small tubercles 

 above extending forwards from the occiput, and with a crenulate 

 carina, beneath which is a dark line, along each side. Pronotum 

 without spines, and bearing only a few very inconspicuous granules. 

 Mesonotum relatively rather short. Metathorax with a conspicuous 

 triangular process on each side, whose edges are somewhat dentate, 

 and with a few lateral cariniform tubercles placed anteriorly. Elytra 

 furnished each with a large, laterally prominent, hump or tubercle 

 near the base. 



