168 SUMMARY OF CURRENT RESEARCHES RELATING TO 



spiracle : it is occasionally ejected from it ; in the ray the current can he 

 definitely reversed for a considerable number of respiratory acts. In 

 Ilh inn the water is drawn into the mouth by the undulation of the gill 

 covers, which are thus active agents in determining the respiratory 

 current. The spiracle in Rhina is only capable of slow and imperceptible 

 opening and closing ; it does not open and shut rhythmically as in the 

 case of the ray and dogfish. 



New Deep-sea Fishes from South-west of Ireland.* — E. W. L. 

 Holt and L. W. Byrne describe the following new species collected by 

 the ' Helga ' — Lremonema latifrons, from 720 fathoms ; Cyttosoma JielgcB, 

 from 540-660 fathoms ; Oneirodes megaceros, from 775-795 fathoms. 



Labyrinth Organ of Labyrinthici.f — G. Henninger describes the 

 structure and position of this accessory respiratory organ in Anabas 

 scandens, Macropodus viridi-auratus, and Trichogaster fasciatus, and 

 relates experiments which show that atmospheric air is used by these 

 fishes. He discusses the afferent and efferent blood-vessels and the 

 rete mirabile in the organ, as also the fact that the heart contains 

 " mixed blood." 



Freshwater Fishes of New Guinea. J — Max Weber points out 

 that the river fishes of New Guinea belong to two groups :— (1) afluvio- 

 marine group, which is Indo- Australian, or Indo- Pacific, and which may 

 be met with, also, for instance, in Ambon or Celebes, and (2) a charac- 

 teristic Australian contingent. Of the latter, 24 in number, none is 

 known from the sea. Of the 12 species of Melanotseniidaj known from 

 New Guinea, and of the 12 species from tropical or sub-tropical 

 Australia, not one is common to the two regions, although the differences 

 between some of the species are very small. The author concludes that 

 the connection between Australia and New Guinea must have been not 

 earlier than in the Pliocene, and the breaking up of it in the Pleistocene. 



Swim-bladder in Scisenidae.§ — L. Cohn describes the complications 

 of the swim-bladder in Collichthys lucida, Otolithus argmteus, and other 

 Scisenids. In some genera, e.g. Corvina, there are species with swim- 

 bladders without diverticula, with simple cornua, with dichotomously 

 forked cornua, and with dendriform outgrowths. In Otolithus gracilis 

 the first pair of diverticula form 3 to 4 branches, and extend for- 

 wards to the auditory capsule, with which the branches are closely 

 connected ; the second pair grow dorsallv, and surround with their 

 branches the under side of the first and second vertebrae ; then follow 

 numerous outgrowths, extending downwards to right and left ; each 

 outgrowth divides into a dorsal branch and a ventral branch, the former 

 branching much more than the latter. 



*& 



Poison-glands of Catfishes.||— H. D. Reed describes the poison- 

 glands of the " stone cats " and " mad toms," species of Nbturus and 



* Ann. Nat. Hist., ser. 8, i. (1908) pp. 86-95 (1 pi. and 1 fig.). 



t Zool. Jahrb., xxv. (1907) pp. 251-304 (4 pis. and 3 figs.). 



% Proc. Acad. Amsterdam, Section of Sciences, ix. (1907) pp. 462-5. 



§ Zool. Anzeig., xxxii. (1907) pp. 433-40 (4 figs.). 



|| Amer. Nat., xli. (1907) pp. 533-66 (5 figs.). 



