880 



THE VOYAGE OF H.M.S. CHALLENGER. 



and about half the length of the third somite, which is also armed with a shorter tooth 

 at the posterior margin, as are also the fourth and fifth somites ; the sixth is nearly as 

 long as the two preceding, and posteriorly projects to a sharp tooth on the dorsal surface 

 as well as at the postero -inferior angle. 



The telson (fig. lz) is nearly as long as the sixth somite, it is posteriorly produced to a 

 long and slender tooth, and armed with several spines on either side. 



The ophthalmus is long-ovate, and equals in length about a third of the carapace. 



The first pair of antennae is scarcely half the length of the rostrum, and the second 

 has the flagellum still less developed. 



The pereionic appendages are in the biramose condition. 



The pleopoda are still undeveloped, excepting the posterior pair (v. v.), which is 

 unequally biramose, and but little shorter than the telson. 



Length, entire, 

 „ of carapace, 

 ,, of rostrum, 

 ,, ofpleon, . 

 „ of sixth somite of pleon, 

 ,, of telson, . 



Habitat. — Cape York, September 6, 1874 ; surface. 



7 mm. (0'3 in.). 



1 „ 



4 „ 



6 „ 



13 „ 



1-4 „ 



Oodeopus duplex, n. sp. (PI. CXLIII. fig. 2). 



Carapace about one-fifth the length of the animal, dorsally smooth, anteriorly pro- 

 jecting to a long rostrum that is about half the length of the animal, and is armed 

 along the lateral margins with a series of small teeth. The orbit is defined at the 

 outer canthus by a small point and the fronto-lateral angle by another, neither being 

 strongly pronounced ; behind the fronto-lateral angle the margin is armed with a series 

 of small teeth. 



The pleon is four times as long as the carapace, and has the first somite dorsally 

 smooth, the second armed with a long tooth, the third with a tooth subequal with it, 

 and the fourth and fifth with shorter teeth ; the sixth somite is equal in length to the 

 three preceding, and is posteriorly produced to a sharp tooth. 



The telson is as long as the sixth somite, has the margin posteriorly tapering, and 

 armed on the dorsal surface and in the median line at the extremity with three spinules 

 and a terminal tooth. 



The ophthalmopoda are more than half the length of the carapace, and support a long- 

 ovate ophthalmus. 



The first pair of antennae is about half the length of the rostrum and terminates in 

 two short, incipient flagella. 



The second pair of antennas is furnished at the distal extremity of the second 



