160 
The sub-median skeleton without processes, but the part obliquely inside and behind the 
base of the maxillze is covered with pretty numerous sete. Shape and hair-covering of the 
lateral margin of the head nearly as in S. dispar; from its posterior extremity the boundary 
of the hairy part proceeds at first vertically upward across the side of the animal, then 
somewhat obliquely backward across the back. The back and sides of the trunk and the 
posterior part of the ventral surface are closely covered with rather long hairs, nearly all 
the remainder of the ventral side has hairs of medium length. Trunk-legs and caudal 
stylets wanting. 
OVISACS. In D. levis they were small, almost globular, with few eggs; in D. 
cornuta they differed considerably in size, from rather small to middle-sized, and were irregular 
on account of mutual pressure. Eges of medium size. 
LARVA. There is no appreciable difference between the larve found in D. levis 
and in D. cornuta. A well-developed free larva from D. cornuta is 20 mm. long and has 
served as type for fig. le—lg. It bears great resemblance to S. dispar, but is sharply 
distinguished by several characters. The cephalothorax like that of the last-mentioned 
species. The decoration of the front is very characteristic (fig. 1f): a transverse list is found 
inside the base of the antennule; further, a sinuate transverse series of processes, with a 
broad central interruption, runs from one antennula to the other; the inner half of this 
series begins far behind the frontal margin, below the anterior side of the rostrum, thence 
it continues in an oblique direction running forward and outward towards the margin, 
consisting only of five or six longer processes; then comes a little break in the row, the 
next process being somewhat further removed from the frontal margin, after which the row 
is continued to the anterior angle of the antennula, but in its latter part the processes are 
shorter than the sub-median ones. The olfactory seta of the antennule is even longer than 
in S. dispar, as, when bent backward, it may reach as far as the posterior end of the 
second abdominal segment. Antenne and maxillule as in the preceding species. Second 
joint of the maxilla without sete (fig. 1g), third joint with three or four processes on its 
inner margin, the outermost of which is longer than the curved extremity of the joint, but 
scarcely longer, at least not considerably so, than the penultimate process. The abdomen 
and its sete as in the preceding species. 
POST-LARVAL DEVELOPMENT. In D. cornuta a single pupa was found (fig. 1h), 
which is ‘14mm. in length and sub-globular. It is described in detail above on p. 56. 
HABITAT. The marsupium of Diastylis cornuta Boeck and D. levis Norm. from 
Denmark. In a specimen of D. cornuta were found: an empty skin of one female, one male 
and seven small ovisacs with young ones in different stages, as well as twelve free larve 
and one pupa. In one specimen of D. /@vis occurred an oblong lump of adhering ovisacs 
surrounding a female; they were irregularly shaped on account of pressure; on one side of 
the lump the larger part of one side of the female was uncovered, and on the side turning 
towards the abdomen of the host, there was a longitudinal impression in the lump, in which a 
