e 
Dr. W. Marshall on new Stliceous Sponges. 391 
yellow spots, much larger than those on the upper surface ; 
pectus yellowish, venter white. Expanse of wings 57 millim. 
Viti Islands. 
Allied to B. tewtonia, but readily distinguishable by the 
absence of orange colouring from the under surface. 
4, Ismene bilunata, sp. n. 
Wings above dark fuliginous brown, growing considerably 
paler towards the base, where there are aféw greenish opaline 
hairs: primaries with two semitransparent white crescents 
placed obliquely before the middle of the median interspaces ; 
fringe of all the wings tipped with white : body above greyish 
brown, the head and prothorax shot with opaline green ; palpi 
sordid white, with a black external lateral line and black ter- 
minal joint. Wings below mouse-brown, primaries with the 
median area blackish, especially towards the base ; crescentic 
markings as above, apical area greyish, bounded internally by 
a transverse elbowed lilacine whitish streak: secondaries 
crossed beyond the middle by a rather narrow and nearly 
straight white stripe, which is interrupted towards its poste- 
rior extremity by a large black quadrate anal patch ; aslender 
white stripe at the base of the fringe, beginning at the black 
patch and running a short distance upwards towards the apex, 
but gradually fading away long before it reaches it: abdo- 
minal area faintly glossed with pink and green tints ; pectus 
greyish; the femora white above, grey at the sides; tibiz 
and tarsi grey above and more or less ochreous below; venter 
creamy white, barred with pale grey. LHxpanse of wings 52 
millim. 
Viti, ‘ Koro” (? Goro). 
Allied to L. alexis 9 of S. India and Ceylon, but differing 
in the smaller crescents on the primaries, the much less lila- 
cine tint of the under surface, and the much more defined white 
stripe across the secondaries. 
XLVII.—On some new Siliceous Sponges collected by M. 
Pechuél-Lésche in the Congo. By Dr. WILLIAM MaRSsHALL*. 
[Plate XV.] 
HXCEPTIONAL forms of animals and plants deviating in some 
respect or other from the general rule have ever excited 
* Translated from a separate copy of the Memoir sent by the author to 
HY. J. Carter, F.R.S. The original appeared in the ‘ Zeitschrift fiir Natur- 
wissenschaften,’ Neue Folge, Band ix. pp. 553-577. 
