THYSANOPODA OBTUSIFRONS. 217 
again to the end, which is truncate and at the posterior margin produced into a 
tooth. The median lobe has the basal part somewhat broad, and the lateral 
process (p*.) is inserted a little before its middle; this process has the basal part 
thickened and the distal fourth bent inwards and forwards; the additional 
process (p*.) is long, only a little shorter than the lateral, moderately robust, 
somewhat curved and overreaching the lobe; the distal part of this lobe is an 
oblong and obliquely triangular lamella which, seen from behind, is bent in- 
wards, covering the proximal half of the additional process. The auxiliary 
lobe is rather long and thick. The setiferous lobe is moderately broad, with 
setae along the major part of both margins, there being a naked interval on the 
subdistal part of the outer margin. 
Length of the largest specimens of both sexes 20 mm. 
Young Specimens.— In specimens measuring only 8-10.5 mm. the rostrum 
is a horizontal denticle and the eyes are oblong, yellowish brown, but at least 
generally without any difference in colour between their upper and lower half; 
the shape of the small lobe from the first antennular joint shows that such 
specimens belong to this and not to the preceding species. 
Remarks.— This species is closely allied to T. aequalis H. J. H., but the lobe 
from first joint of the antennular peduncle is quite different in the two species, 
and the male copulatory organs are sharply distinguished especially by the 
feature that the spine-shaped process is well developed in 7. obtusifrons and 
wanting in 7’. aequalis. 
Errors and deficiencies in Sars’s figures have been pointed out in the “‘Si- 
boga”’ Report; besides Sars states that the lateral margins of the carapace have 
no denticle, but a minute denticle is always present. 
Distribution.— Sars’s type was captured in the South Pacifie at Lat. 32° 36’ 
S., long. 137° 43’ W., but the specimens from the Hawaiian Islands mentioned by 
Ortmann (1905) belong to 7. aequalis. A good many specimens were captured 
by the Prince of Monaco in the Eastern Atlantic between Lat. 36° 46’ N. and lat. 
27° 43’ N. The Copenhagen Museum possesses a specimen from Lat. 27° 30’ S., 
long. 98°-99° 10’ E. 
The distribution in the area explored in 1904-1905 is nearly the same as that 
of T. aequalis, but less common. Curiously enough, it has not been taken by 
the “Siboga” and is not found among the rather rich Copenhagen material 
from the Chinese and Japanese seas. 
8B. Carapace in the adults without denticles on the lateral margins near their 
posterior end. 
