1S8G.J 77 



NOTE ON SOME BEITISH COCCIDM (No. 4). 

 BY J. W. DOUGLAS, F.E.S. 



Lecanium alienum, n. sp. 

 For three or four years past a house-fern (Asplenium huJliferum) 

 has been infested with a Lecanium to that extent that the fronds have 

 withered under the constant attacks of the individuals that, in all 

 stages of life and overlaying each other, cover them constantly except 

 in the winter months. 



When young the scales are flat and yellowish, very like L. hesperidum at the 

 same age ; at a later stage they mostly become faintly maculated. When full-grown 

 they are, at the maximum, 3 J mm. long by 2f mm. broad at the widest part, forming 

 a long oval much widened posteriorly, convex, pale greenish-yellow, the disc with 

 fuscous, coarse, irregular reticulation, anteriorly and posteriorly forming wide, darker 

 transverse patches or bands, the meshes having rounded pale centres, but in the 

 middle of the disc, on each side of a broad, dark longitudinal line, the ground- 

 colour shows as a large pale patch, and similarly as two smaller spots anteriorly ; 

 on the dark median line are usually 4 — 5 very minute yellow elevations in a row ; 

 the prominent anal point above the fissure deeper yellowish ; the margin wide but 

 scarcely flattened, with strong, black-dotted, transverse, parallel lines throughout. 

 On the under-side the body of the insect is pale anteriorly, fuscous-black posteriorly ; 

 the antennae pale, of seven joints, of which the 3rd is the longest. The adult scales 

 always cover oval yellow embryonic active larvte, so that the females are doubtless 

 viviparous. When removed from the fronds and dried the adult scales become of a 

 uniform pale brown, and the sides curve under, so that the form is changed. I have 

 not found a male. 



In form this species is somewhat like L acuminatum. Sign., but 

 that is only 2 — 3 mm. long, and appears to be without markings. 



It differs from L. angustatum, which is narrow throughout, 4 — 5 

 mm. long by 2 mm. broad, of a clear yellow^ colour (apparently without 

 markings), smooth and very flat ; whereas this is wide posteriorly, 

 distinctly convex, and is marked as stated. 



It appears to resemble L. maculatum, Sign., only in being elongate 

 oval, but that is a more regular oval, and has a median series of 8 or 

 9 brownish spots, which it is stated specially distinguish it from L. 

 hesperidum. 



The reticulation seems to ally it to L. tessellatum, Sign., the form 

 of which is given as broad-oval, much rounded posteriorly, and some- 

 what flattened, the colour is red-brown, the size 3^ mm. by 3 mm., 

 and the surface exhibits throughout a design of marquetry of irregular 

 fine lined pattern, without other marking ; whereas in L. alienum the 

 form is long-oval, convex, and the reticulation and markings are 

 formed of strong, dotted, dark lines. 



