338 On a new Australian Species o/" Thyrsites. 



of a body-cavity, which are of the utmost value. He adopts 

 a more detailed nomenclature than I have used here, and does 

 not take the same view of the water-vascular system of flat- 

 worms as I have done ; but to some extent there is naturally 

 coincidence, due to the fact that the material here used in the 

 form of facts has been mainly drawn from his other writings 

 and those of other German and Russian embryologists. I have 

 not attempted to discuss Professor Hackel's views nor referred 

 to his terms, chiefly because the substance of this paper was 

 drawn up before the ' Kalkschwamme ' appeared. 



XXXVI. — On a new Australian Species 0/ Thyrsites. 

 By Prof. Frederick M'Coy. 



The common Barracoota of the Cape seas is very abundant in 

 the Melbourne market from the adjacent coast, and has long 

 been known ; but an equally large and important species for 

 food is brought in great quantities from Tasmania to the 

 Melbourne fish-shops, usually split open and dried ; and, as far 

 as I can see, it has been overlooked by naturalists. It is easily 

 distinguished at a glance from the Thyrsites atun or Barracoota 

 by the much greater depth of the body, fewer finlets, shorter 

 dorsal, larger teeth, and double lateral line ; but the mode of 

 preparation usually obscures the still more striking character 

 of the ventrals being almost absent, or at least very minute 

 and rudimentary. I subjoin a description of the species. 



Thyrsites micropus (M'Coy). 



D. 17 I 4-M2 1 VI. A. 2 + 11. IV. V. 1 -f- 1 (bifurcate). 

 P. 14. C. 22f . 



Height of body five times in total length to centre of caudal 

 fin ; head four times to end of lobes of caudal. Lower jaw 

 projecting in advance of the upper ; diameter of orbit one fifth 

 the length of the head, and one half the length of the muzzle. 

 Ventrals each with one spine and one bifurcate ray, slightly in 

 advance of base of pectorals ; about one third the diameter of 

 the eye in length. Lateral line bifurcate : upper branch ex- 

 tending from a little above the operculum, a little below the 

 dorsal line, as far as the third finlet ; lower branch coming off 

 from upper one under base of fifth dorsal spine, and descending 

 with an abrupt curve nearly to the middle of the side, con- 

 tinuing nearly straight to opposite middle of anal fin, from 

 which to middle of tail it describes three upward undulations. 



