ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 293 



condition in which the maxilla bears teeth throughout its length, and 

 that where the maxilla is toothless, and so reduced as to be practically 

 excluded from the gape. 



Notes on Loricariid Fishes.* — C. T. Regan finds that Plecostomus 

 horridus Kner., is probably P. tenuicaudata Steind. ; it is certainly dis- 

 tinct from P. emarginatus C. and V. A fresh description of the species 

 is given. P. Oarmani Regan, is not equivalent to P. lima atropinnis 

 Eigenm., but to P. lima Eigenm. Thysanocara is proposed as a new 

 sub-generic name for Xenocara cirrhosum and its allies. X. brevipinnis 

 Regan is re-described. Other notes and descriptions are also given. 



Flying-Fish Flightf— C. D. Durnford discusses this subject. He 

 is of opinion that flying-fish would require to have a wing-area several 

 (and probably many) times greater, according to their weights, than 

 they actually possess, to enable them to accomplish sailing flight in even 

 such a restricted form as that carried out by sailing birds. We know of 

 no parallel case in Nature which would justify the assumption that the 

 possession by these fishes of even such increased fin-area would, of 

 necessity, enable them to sail long distances (a) horizontally, or (b) 

 close to an obstruction (the sea), or (c) in defiance of the direction of 

 the wind ; much less all three combined, as they commonly fly. Their 

 common flight is exactly what is to be expected of fliers holding, as they 

 do, a very low wing to weight ratio — fliers capable of, and of necessity 

 employing, extreme wing-speed. 



Dipnoan Affinities of Arthrodires.J — C. R. Eastman finds that 

 Neoceratodus bears intimate resemblances to Arthrodires on the one 

 hand, and to Ctenodipterines on the other, but represents a more primi- 

 tive structural type than either. Community of origin is necessarily 

 presupposed for Sirenoids, Ctenodipterines, and Arthrodires. Arthro- 

 dires and Ctenodipterines may be regarded as specialised offshoots in 

 different directions from primitive Dipnoan ancestors ; and the more 

 generalised descendants of the latter have alone survived until the 

 present day. The primitive stock must have been autostylic, diphycercal, 

 without a secondary upper jaw, and dentigerous, dentary elements ; and 

 with Urommus- or Dipterus-liie type of dentition — characters which do 

 not permit us to ascribe the ultimate origin of Dipnoans to the Crosso- 

 pterygii, but suggest rather a descent from Pleuracanthus-libe sharks. 

 The recognition of Arthrodires as an order of Dipneusti precludes their 

 association with Ostracophores in any sense whatever, and the unnatural 

 assemblage of " Placodermata " must be given up. 



Respiration and Circulation in Monopterus javanicus.§ — W. Yolz 

 finds a number of peculiarities in this Malayan Symbranchid, which 

 " sleeps " in the dry season. The heart is unusually far from the head, 

 and the aorta is formed (as in Amphinous cuchia) from the fourth pair 

 of branchial arteries. The three anterior pairs take the blood especially 

 to the superior wall of the pharynx ; the gills are much reduced and 



* Ann. Nat. Hist., xcvii. (1906) pp. 94-8. t Tom. cit., pp. 158-67. 



$ Amer. Journ. Sci., xxi. (1906) pp. 131-43 (4 figs.). 

 § Arch. Sci. Phys. Nat., xx. (1905) pp. 580-1. 



