480 Dr. Fritz Miiller's contribution towards the 
and, therefore, can hardly be taken hold of singly. The 
flat of the hand is, therefore, passed over the slippery 
wall, the surface of the hand is scraped with a knife, 
which is then rinsed in a tumbler of fresh water; the 
larvas thus obtained are soon found fastened to the sides 
of the tumbler, the muddy water of which is then 
replaced by fresh. Unlike the Curupira-larvse, which 
die very soon, those of Maruina bear confinement very 
well, change into pupae, and the majority of the latter 
produce flies in a week or two. Whether the mould 
which appears on pupae very soon after they are dead, 
is the cause of the death, or its consequence, I 
cannot say. 
Three kinds of larvae are easily distinguished : two of 
them have the appearance of woodlice [onisciform, 
O. S.) ; their abdominal segments bear on each side 
straight thorns, the length of which is much less than 
half a breadth of the abdomen ; in one of the species, 
Maruina pilosella (figs. 2, 3, 4) they are simple, in the 
other {M. spinosa) they have from four to six, seldom 
seven, branches. The third species, M. Ursula, which, 
in many respects, is very aberrant (fig. 1), bears on each 
of the abdominal segments three pairs of very long and 
very much curved bristles, of which one pair is inserted 
very near the lateral margin of the segment, and two 
pairs, close by each other, are placed on one of the 
three dorsal plates of the segment. The abdominal 
segments of the two other species likewise show three 
dorsal plates on each abdominal segment, and laterally 
these segments are very conspicuously divided into 
three lobes (fig. 4). A character that the three sp^'ies 
of larvae have in common is the head, which is much 
narrowed in front, and has on its upper side two small 
eyes, placed near the middle of the lateral margin; a 
little inside and in front are two short antennae, without 
any joints, and still more inside of these are two minute 
punctured spots (figs. 1 and 3). 
In Maruina pilosella and spinosa the last abdominal 
segment projects but little beyond the penaltimate 
segment, which rounds off* the end of the abdomen 
(fig. 2) ; in Maruina Ursula this last segment takes the 
shape of an elongate, bot-tle-shaped projection, at the 
end of which the two principal branches of the trachae 
meet. These openings are surrounded by a coronet of 
