THYSAXOPODA ORTUSIFROXS. 217 



again to the end, which is truncate and at the posterior margin produced into a 

 tooth. The median lobe has the l^asal 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 tluin the lateral, moderately robust, 

 somewhat curved and overreaching tlie lol)e; the distal part of this lobe is an 

 oblong and obli(|uely 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 im the 

 subdistal part of the outer margin. 



Length of the largest specimens of both sexes 20 mm. 



Young S])ecime)}s. — In specimens measuring only 8-10.5 mm. the rostrum 

 is a horizontal denticle and the eyes are oblong, yellowish l)rown, but at least 

 generally without any difference in colour l)etween their upper and lower half; 

 the shape of the small lof)e from the lii-st antennular joint shows that such 

 specimens belong to this and not to the preceding species. 



Ranarks. — Tliis species is closely allied to T. acquaJis H. J. H., but the lobe 

 from first joint of the antennular peduncle is (|uite different in the two species, 

 and the male copulatory organs are sharply distinguished especially liy tlie 

 featui^ that the spine-shaped process is well developed in T. nbtusifrons and 

 wanting in 7'. (uqiKilis. 



Errors and deficiencies in Sars's figiu'es have been pointed out in the "Si- 

 boga" Report; besides Sars states tliat the lateral margins of the carapace have 

 no denticle, but a minute denticle is always present. 



Di.slribution. — Sars's type was cajitured in the South Pacific at Lat. 32° 3G' 

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

 Ortmann (1905) belong to T. uequalis. \ good many specimens were captured 

 I)y the Prince of Monaco in the Eastern Atlantic between Lat. 36° 4(5' N. and lat. 

 27° 43' N. The ('o])enhagen Museum i)ossesses a specimen from Lat. 27" 30' S., 

 long. 9S°-99° 10' E. 



The distribution in the area exjilorcd in 1904-1905 is nearly the same as tliat 

 of T. aequalis, but less connnon. Cui'iously euougli, it has not been taken liy 

 the "Siboga" and is not found among llic rather i-icli ( 'openliagen material 

 from the Chinese and .lai)anese seas. 



f3. Carapdcc in (lie (iilull.'< irillimil il( nliclis on tite hittrol nnirgins near their 

 posterior end. 



