274 THE ATRYPIDAE OF XEW SOUTH WALES, 



this species by the late Mr. K. Etheridge, Jim., and after a very critical exataina- 

 tion of it, coucliide that it is not A. reticularis, but an immature A. desquamata. 

 Our reasons for this conclusion are the prominent beak, the exposure in the 

 specimen of an area, and the strong curvature of the lateral ribs towards the car- 

 dinal angles. In addition, the alleged A. reticularis is represented in the Mu- 

 seum of the Geological Survey, Brisbane, only by the single specimen which served 

 Mr. Etheridge Jr. for his determination. This of itself is a very suggestive fact, 

 for A. reticularis was a very gi'cgarious brachiopod and wherever it occurs, does 

 so, almost without exception, in numbers. It is also worthy of remark, that this 

 fossil occurs in association with numerous individuals of Atrypa desquamata; a 

 circumstance which supports the contention that it is an immature specimen of 

 the latter species. 



Atrypa desquamata J. de C. Sowerby. — The occurrence of this brachiopod 

 is also recorded by Mr. Etheridge Jun.§ It is found plentifully in the middle 

 Devonian Rocks outcropping in the valley of the Fanning, Burdekin and Broken 

 Rivers in the Burdekin Downs District, and the specimens collected from this 

 locality agree very fully with the original types. In New South Wales, to my 

 knowledge, A. reticularis has never been found in association with A. desquamata. 

 May this not be the case also in Queensland? In England, the two species are 

 found commingled in Middle Devonian Rocks. 



Victoria. 



F. Chapman* has recorded the occurrence of A. reticularis var. decurrens 

 from the Yeringian of Yeriug and Loyola; A. aspera Schloth. from Loyola and 

 the Middle Devonian of Bindi; and A. fimbriata from Lilydale. The latter form 

 he compared with ^1. hystrix and A. spinosa J. Hall from the Chemung and 

 Hamilton Groups of N. America. In general these forms have extra- Australian 

 Devonian affinities. 



Mr. Chapman observes with reference to the occurrence of .1. reticularis 

 that he tinds it to be very common in the limestone beds and much less common 

 in the shales of the Yeringian beds of Victoria. In the Downing- Yass beds of 

 New South Wales, the same thing is noticeable, and it appears that this preference 

 for clear sea Hoors on the part of this reniarkal)!e brachiopod is manifest in every 

 part of the world where it is found. With reference to his A. aspera, recorded 

 from the Yeringian beds and which he says had been recorded from tlie Silurian 

 and Devonian of Victoria previously by McCoy, it must be observed that the 

 latter regarded it as a variety of A. reticularis. We have some doubts as to the 

 correctness of this determination, though it must be admitted that the concentric 

 lamellae exhiliited liy Mr. Chapman's species closely resemble tliose of the ori- 

 ginal type. Whether Mr. Chapman's conclusion is right or not, it must not be 

 overlooked that many palaeontologists recognise A. aspera only as a variety of 

 A. reticularis. 



Atrypa reticularis var. decurrevs, to ns, seems a slightly abnormal A. reticu- 

 laris. Some similar specimens have been noticed by one of us from the Bowning 

 Beds. ,1. fmhriata Chapman is a very interesting species and as Mr. ('lia)iman 

 points out is very like A. hystri.r J. Hall. Notliing similar has yet been collected 

 from New South Wales. Mr. Chapman t has also recorded ^1. reticularis from 

 O'Keefe's Gully, Aberfeldy River, and Atrypa sp. from Tyer's River. 



§Aof. rif. 



•Proc. Roy. Sec. Vict., xxvi., (N.S.), Pt. i., 1913, pp.107-109. 



+Rec. Geol. Survey Vic, ii., Pt. i., 1907, pp.68, 71. 



