418 On a new Species of Nebalia y?'om New Zealand. 



smooth on its inner margin, or only slightly denticulated. 

 Second gnathopoda very slender. Posterior pleopoda bearing 

 a smooth sickle-shaped finger, with a few long cilia at its 

 base. Terminal uropoda almost as long as antennae, five- 

 jointed, and with numerous seta?. Length 0*18 inch. 



Ilab. Dredged along with the previous species in Dunedin 

 Harbour, in 4-5 fathoms. 



EXPLANATION OF PLATE XIX. Figs. 1-6. 



Fig. 1. Arcturus tuhereulatus (male). X 13. 



Fig. 2. The same (female), head and part of body, x 13. 



Fig. 3. The same, superior antenme. X 56. 



Fig. 4. The same, lamellar plate of abdomen. X 28. 



Fig. 6. Tanais nova-zealandire. X 13. 



Fig. 6. The same, extremity of last pair of legs. X 28. 



XLVIT. — On a new Species o/'Nebalia from New Zealand. 

 By George M. Thomson. 



[Plate XIX. figs. 7-9.] 



In dredging during the past summer in Dunedin Harbour 

 I obtained a single specimen of a Nebalia differing from any 

 species hitherto described, and which, from the great length 

 of its inferior antenna?, I have named N. longicornis. 



In a paper in the Linnean Society's Transactions for 1875 

 (ser. ii. vol. i.), "On some Atlantic Crustacea of the ' Chal- 

 lenger' Expedition," Dr. Willemoes-Suhm described a new 

 species of Nebalia from Bermuda (N. longijoes), in which 

 the phyllopodal character of the legs has been entirely lost, 

 and the schizopodal character approached more than in any 

 other species of the genus. Taking this fact in conjunction 

 with the characters of several new deep-sea genera of Sehizo- 

 pods examined by him, he reopened the whole question of the 

 position which Nebalia occupies in reference to other groups 

 of Crustacea, and proposed to unite it with these new forms, 

 the Mysidse, &c, in the enlarged group of the Schizopoda. 

 Seeing, however, that it differs from all others of the family 

 in the number of its segments, in the well-developed phyllo- 

 podal character of the thoracic appendages in the majority of 

 the species, and also in its development, it seems a better 

 plan to adopt the proposition made by Dr. A. S. Packard, Jun. 

 (in the ' American Naturalist,' vol. xiii. p. 128), viz. to make 

 it the type of a new order, the Phyllocarida. As he points 

 out, Nebalia probably represents a persistent form of a very 



