286 THE SCHIZOPODA. 
shorter with the exopod setiferous but no endopod. Third to fifth pair nearly 
rudimentary, oblong, with a transverse suture but without setae.— The uropods 
reach nearly the proximal pair of spines on the terminal part of the telson. 
This terminal part (fig. 1g) is very different from that of first Furcilia-stage; 
the terminal margin is convex with only five spines and the median spine longer 
and stronger than the others, which are a little shorter than in the earlier stage; 
of the distal lateral spines the intermediate pair are nearly as in the preceding 
stage (in the single specimen the left spine is normal, the right shorter and without 
fine marginal spines), the proximal pair are short and slender, while the distal 
pair are longer and stronger than the intermediate, straight, with only two or 
three fine spines on the inner margin. 
Length of the single specimen 5 mm. 
The specimen is from ‘‘ Albatross” Sta. 4710; December 30, 1904. Surface. 
Remarks.— That the two stages described belong to the same species is 
easily seen from the shape of the frontal plate, the antennulae, the eyes, and the 
second abdominal segment. It is closely allied to 7. monacantha Ortm. (T. 
agassizii Ortm.) but can scarcely be that species. The “‘Siboga” material 
contained specimens of the last Furcilia-stage, furthermore a young animal in 
which the process from the two proximal antennular joints had begun to develop 
—so that this specimen could with absolute certainty be referred to 7’. mona- 
cantha — and besides two stages intermediate between the last-named speci- 
men and the last Furcilia-stage, and it is quite sure that all these specimens 
belong to the same species. But the specimens in the last Furcilia-stage from 
the “‘Siboga” differ from the specimen in the Agassiz collection just described 
by having the body a little shorter and somewhat more clumsy, the eyes some- 
what larger, the frontal plate a little different in shape, the second abdominal 
segment less protruding above and besides showing an interesting difference in 
the telson. Though the thoracic and abdominal appendages show the same 
degree of development in the specimens in last Furcilia-stage from both col- 
lections, the Agassiz specimen, which is a little longer than those from the 
“Siboga,’’ has the distal part of the telson less developed than the “‘Siboga”’ 
specimens, as the long postero-lateral spines of the intermediate pair found in 
the Agassiz specimen are lost in the “Siboga’”’ specimens (Siboga-Exp., 37, 
pl. 18, fig. 3g). 
It is, I think, very improbable that the differences pointed out between 
specimens in the last Furcilia-stage from the Indian Archipelago and the tropical 
East Pacific can be found in larvae of the same species from two distant areas. 
