MYSIDJE. 27 



which persist throughout life in both sexes. The chief dif- 

 ference is that in one type, the neural centres are paired 

 throughout the thoracic region ; but only occur opposite to 

 the third, sixth, and eighth appendages in the other type. 

 The first type we call M. flexuosa, the second M. niyra }: 

 (KeeUe fy Gamble). 



Abundant about Drake Island, Plymouth, and Starcross 

 (A. M. .A 7 .); Salcombe (Beaumont, vi. p. 202). 



MACROMYSIS INERMIS (Rathke). 



A common species. Salcombe, Plymouth, Scilly Isles 

 (A. M. A".); with spawn at Plymouth in June (Garstang). 



SCHISTOMYSIS SPIRITUS, Norman. 



Plymouth Sound and Whitsand Bay (A. M. N., 1903); 

 with spawn at Plymouth in June, July, and August (Gar- 

 stany, iii. p. 227). 



SCHISTOMYSIS PARKERI, Norman. 



1892. Schistomi/sis Parkeri, Norman, " On British Mysidse," Aun. & 

 Mag. Nat. Hist. ser. 6, vol. x. p. 250, pi. x. tigs. 1-7. 



The types were taken by Mr. C. Parker near Starcross, 

 in 1884. Plymouth (from Biol. Lai. in Mus. Nor.); one 

 taken between Pole and Monster Sands in the Exe Estuary 

 (Todd, vi. p. 324) ; St. Ives, 1905 (Vallent'm !). 



SCHISTOMYSIS ORNATA (G. 0. Sars). 



A young specimen was sent to A. M. N. by Dr. Gough, 

 which had been taken in the tow-net at Stat. 7 (Internat. 

 Comm.), that is off Mounts Bay, November 1903. Off 

 Plymouth and in the Tamar Estuary (Holt fy Beaumont). 



SCHISTOMYSIS HELLERI (G. O. Sars). 



Starcross and Plymouth (.4. M. N.); Salcombe (W. I. 

 Beaumont, vi. pp. 202 & 324). 



SCHISTOMYSIS ARENOSA (G. 0. Sars). 



Starcross, 1884 (C. Parker, in. Mux. JVor.); Whitsand Bay 

 (A. M. N.); Salcombe (Beaumont, vi. p. 202); with spawn at 

 Plymouth in June (Garstang, iii. p. 227). 



ACANTHOMYSIS LONGicoRNis (H. Milne-Edwards). 



1837. Mysis longicornis, H. Milne-Edwards, Hist. Nat. des Crust, 

 vol. ii. p. 459, pi. xxvi. figs. 7-9. 



1840. Mysis lonr/icornis, Heller, Crust, siidl. Europa, p. 302. 



1876. Mysis loiifftcorin's, G. O. Sars, "Nye Bidrag til Kunds. 

 om Middelhavets Invertebratfauna, I. Middelhavets Mysider," 

 Archiv f. Math, og Naturvid. p. 22, pis. ix. & x. 



