482 ME. a. M. THOMSON ON 



On some New Zealand Schizopoda. 

 By Geo. M. Thomsoi^, F.L.S. 



[Read 7th December, 1899.] 



(Plates 33 & 34.) 



Though so many species of Crustacea have been described 

 from New Zealand from time to time, yet tbe amount of col- 

 lecting wliicli lias been done in tbe Colony, and especially in the 

 North Island, is really very small. The result is that only a few 

 individuals, representative of whole families, have in many cases 

 been recorded. 



Trawling is now becoming common, and the opportunity of 

 securing material in this manner will no doubt be more or less 

 utilized. But up to the present, and excluding the fragmentary 

 collections made during the ' Challenger ' Expedition, nearly all 

 the material hitherto studied has been obtained by shore collectors. 

 The specimens described in this paper come under the same 

 heading: they are the only Schizopod crustaceans which have 

 yet been found in New Zealand waters, but probably the group 

 will be found to be well represented. 



Schizopoda. 



Earn. MysiDiE. 



Genns Sirtella, Dana. 



SlEIELLA JDENTICULATA. (PI. 33. figS. 1-5.) 



Mysis denticulata, Thomson, Ann. & Mag. Nat. Hist, ser, 5, vol. vi. 

 p. 1,11880 ; Trans. N. Z. Inst. vol. xiii. p. 205, pi. vii. fig. 6, 1881. 



This species appears to be intermediate in most of its characters 

 between S. Thompsoni, M.-Edwards, and S. gracilis, Dana. I had 

 provisionally included it in the former ; but Prof. G. 0. Sars, to 

 whom I sent specimens, considers it to be a new species. 



It resembles S. Thompsoni in the acutely pointed frontal pro- 

 jection, in the large eyes with greatly expanded cornea, in the 

 general form of the telson, and in size. 



On the other hand, its affinities with S. gracilis are seen in 

 (1) the slender form of the body, (2) in having the last joint of 

 the antennular peduncle rather short and stout, as in fig. 1, 

 (3) in the form of the antennal scale, (4) in the divided propodal 



