On the Genus Lasiodora, C. Koch, 337 



mucli used by Dr. A. S. Woodward, tliat in evolution the 

 dermal fin-rays become correlated with the eudoskeletal tin- 

 supports. 



Finally, as all Osteolepids have an archipterygial fin, with 

 only a single element articulating with the pectoral girtlle, we 

 have to take into consideration the somewhafc Teleost-like 

 skeleton of the pectoral fin found in Ccelacanthus accoxiWw^j^ 

 to Well burn and in an undetermined Coelacanth described by 

 Smith Woodward. 



The whole literature is listed and discussed in E. A. Stensio, 

 ' Triassic Fishes from Spitzbergen' (Adolf. Holzhausen, 

 Vienna, 1921). 



I have to acknowledge my indebtedness to Mr. G. E. 

 Dibley tor the loan of specimens, two oE which proved 

 invaluable in my studies. 



XXX. — On the Genus Lasiodora, C. Koch. By JMkllO- 

 LeitaO, M.D., Fellow of the Brazilian Society of Sciences. 



The genus Lasiodora, C. Koch, is essentially neotropical, and 

 all its species but one {L. iceijenlieryldy Thorell, from Argen- 

 lina) are found in the Brazil!;. n fauna. I have seen in the 

 collection of the Natural Histoiy ^luseums of S. Paulo and 

 llio de Janeiro specimens of all the Brazilian species. 



Lasiodora differs from all the other Lasiodorese, Simon, in 

 having a stridulating-organ similar to that of Gramniostoia ; 

 but in Lasiodora the stridulating bristles are much less 

 numerous, and those on coxa i. are situated only u|)on the 

 suture. The characters of this stridulaiing-organ distinguish 

 the species, the number and disposition of the stridulating 

 bristles being variable. I give the following t.ible of Bra- 

 zilian species : — 



A. Falces with a rose-tliorn-like spur in the 



external surface acanthognathd, sp. n. 



AA. Falces Avitbout exteiual spur. 



B. 8tridulatiuo-oi|:auwith uulythreelarj^e 



bristles upon the suture on coxa i. . . dulcicola, sp. n. 

 BB. Stridulating-organ with more than 

 seven bristles upon the suture on 

 coxa i. 

 C. Stridulating-organ with some short 



stout spines on the anterior side of f- 



ccxa i. amongst the stridulating 

 bristles (median anterior e_yes larger 

 than laterals). 



Ann. c£; Mag. N. IJist. Ser. 9. Vul. viii. 22 



