80 AIR. E. S. GOODRICH ON THE 



pp. 44-84, Taf. iii.-v.), discusses new Dragonflies from Formosa, 

 South China, Tonkin and the Philippine Islands. Amongst others, 

 two species of the genus Idionyx are described as new. In the 

 case of one of these, 7. claudia Ris, from Tsa- Yin-San, the male 

 carries on the under side of segment 7 of the abdomen a brush of 

 hairs exactly similar to that which I have described as occurring 

 in /. dohrni horneensis. Dr. Ris figures this feature in his paper 

 [loc. cit. p. 83, fig. 18). The second paper (Tijdschrift voor 

 Entomologie, Deel Iv. 1912, pp. 158-182, pis. 6, 7, 8) contains an 

 account of Odonata from Java and Krakatau. The characters of 

 the genus Disparoneura and Caconeura are discussed, and a 

 specimen of D. humeralis from Mula (Java) is recorded. 



6. On the Structure o£ Bone in Fishes : a Contribution 

 to Palfeohistology. By Edwin S. Goodrich, M.A., 

 F.R.S., F.Z.S., Fellow o£ Merton College, Oxford. 



[Received November 7, 1912 : Read November 26, 1912.] 



(Text-figures 13-16.) 



Index. Page 



Morphology 80 



Phylogeny of Teleostei 83 



In a paper on the Scal&s of Fishes, published in the ' Pro- 

 ceedings ' of this Society five years ago (1), I showed that the 

 so-called "Ganoid" scales are of two kinds, differing funda- 

 mentally in minute structure and mode of growth. Scales of the 

 fii-st kind, to which the name Cosmoid was given, are typically 

 covered with an outer layer of cosmine, and grow by the addition 

 of new cosmine at the edge and new layers of bony tissue on the 

 inner surface. The second kind, the true Ganoid scale, grows by 

 the addition of new complete concentric layers, formed of cell- 

 less ganoine on the outer surface and bony tissue on the inner 

 surface. Cosmoid scales are found in the Dipnoi and Osteolepidoti 

 (extinct Crossopterygii), and in these only. True Ganoid scales 

 occur only in the Actinopterygii and Polypterini (which probably 

 belong to the Actinopterygii, 2). Moreover, it was further 

 shown that the Ganoid scales can also "he distinguished into two 

 varieties— the Palseoniscoid and the Lepidosteoid. The former 

 is characterised by the presence of a middle cosmine-like layer, 

 and occurs only in the Chondrostei (Palseoniscidse and their 

 allies) and in the Polypterini ; while the latter variety — the 

 Lepidosteoid scale — isfound in the Orders Amioidei(Protospondyli, 

 4- Pholidophoridse, and Oligopleuridee) and Lepidosteoidei (Lepi- 

 dosteidaj and Aspidorhynchidse). The lepidosteoid scale is easily 

 distinguished by the absence of the middle cosmine-like layer 

 and by the presence of a system of delicate tubules running 

 through and at right angles to the bony layers. The tubules have 

 been described by Reissner (6), Hertwig (3), and Nickerson (4) 



