BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 11. N:o 9. 11 
are not placed on a crista or frame as in the preceding spe- 
cies, but rise directly from the surface of the head. On the 
under-side of the head there is no shorter row of spines as 
in Th. Nepturius and Th. pellucida. 
The eyes occupy only the upper parts of the head and 
are united in the median line. ; 
The first pair of antenne (Fig. 2) are fixed on the under- 
side ofthe head a little behind the anterior end; they consist of two 
joints. The second joint is more than four times longer than 
the first (9: 2); it shows traces of having been diveded into three 
equal joints. (Fig. 2). They are not provided with hairs, 
bristles or glands. At the tip of the last joint is a minute spine. 
The second pair of antenne consist of two small sharp- 
pointed tubercles situated at the under-side of the head, closer 
to the hinder than to the anterior margin. 
The mouth consists of a small, nearly straight labrwm; a 
pair of rounded mandibles (Fig. 3) closely beset with short 
spine-like bristles and provided with a small molar tubercle, 
but destitute of a palp. After the mandibles two pairs of 
maxzille follow as usual. The first pair consist of two lamine; 
the inner carries strong teeth along the inner margin, 
the lower is finely serrated at the tip (Fig. 4). The se- 
cond pair consist of only one lamina feebly serrated at the 
tip. (Fig. 5). Thereafter follow the coalesced maxillipeds, con- 
sisting of two stout peduncular joints and a median tongue, 
truncated at the anterior end; on both sides of this tongue are 
the lamine representing the palps; they are strongly serrated 
along the inner margins. (Fig. 6). 
The segments of the pereion are inflated, tuberculated. 
The first and second segments are very deep, much deeper 
than the following; the first is a little shorter than the second; 
the seventh is the longest. The third to seventh segments 
are marked with a feeble ridge indicating the epimerals. This 
ridge carries very minute spines on the seventh segment and 
continues along the pleon and urus, which are also spinulous. 
On the dorsal side runs a sharp keel without spine-like tubercles 
on the four first segments, this keel continues on the pleon 
and urus, with exception of the last ural segment, the posterior 
margins of all the segments are bordered with minute spines. 
The first pair of pereiopoda (Fig. 7) are a little more 
than a third of the length of the third pair. The femur is almost 
