TIIYSANOPODA OBTUSIFRONS. 217 



again to the end, whicli 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 lol)e; 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 tlie 

 subdistal part of the outer margin. 



Length of the largest specimens of both sexes 20 mm. 



Youug 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. 



Re7narks. — 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 T. obtusifrons and 

 wanting in T. 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 Pacific at Lat. 32° 36' 

 S., long. 137° 43' W., l)ut the specimens from the Hawaiian Islands mentioned by 

 Ortmann (1905) belong to T. 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. 



/8. Carapace in the adults without denticles on the lateral margins near their 

 posterior end. 



