114 SOME AUSTRALIAN BRACHIOPODS, 



R.S. TAS. 



locality is about 500 km. distant from Twofold Bay, vrhere 

 the Challenger example comes from. It may consequently 

 be assumed that this species extends to the South *nd 

 the South-East Coast of Australia. 



2. Teiiebratella Mayi, n. sp. (Plate xi., fig. 7, 8, 9.) 



A small kind, nearly as long as broad. Greatest breadth 

 in the middle. In the front half of the dorsal valve a 

 faint median sinus. Growth-strise distinctly to strongly 

 developed. Ribbing slightly pronounced, and quite absent 

 on the older* parts of the shell. Beak, in young examples 

 with faintly, in older ones distinctly, developed edgee. 

 Deltidial plates in the illustrated example touching each 

 other. In the largest example (from which fig. 9 is 

 derived) they are separated, which possibly results from 

 absorption in the dead shell. The Brachial apparatus is 

 not completely preserved in any of the examples (only 

 empty shells are displayed), yet they show, aa we can con- 

 clude from the remnants, the characters of Terehratella 

 dorsata (fio-. 9). There is a bigh median-septum developed, 

 which is connected at the back with the hingeplate. At 

 the point where the connection of the descending limb 

 reaches the septum, this subsides, curving gently towards 

 the front, to end rather far in front of the middle of the 

 Yalve. The described general characters of the shell would, 

 apart from its small size, hardly suffice to permit a defi- 

 ?iite distinction of the jtresent species from 1\ dorsata. 

 Nevertheless, the characters of the pores provide clear 

 distinction. 



Terehratella mayi— outev surface of the middle part of 

 the dorsal valve (10(3 x , 9 sq. mm.) 



The nunaber of pores in the sq. nun. amount to 300 (in 

 T. dm-saia, 180-212). Th<! inner diameter of the shell 

 tubes is U)fi., and the outer oval opening of the same 

 measures 60/35^. 



