BY EDWIN ASHBY, F.L.S., M.B.O.U. 39- 



difference, that in the fossil the margin is almost straight, 

 whereas in the two species referred to, it curves outwards 

 under the jugum, in a semi-circle. 



Note. — The strength and character of the sculpture 

 easily separate this species from any other of the known 

 fossil Loricella. 



Loricella angasi, Ad. and Ang., and L. torri, Ashby. 



In my paper on the genus Loricella (Trans. Roy. Soc. 

 of S. Austr., Vol. XLIIL, p. 61, 1919) reference is made to 

 the lobed suture of the inside of the median valve of L. 

 angasi, but only the superficial features distinguishing L. 

 torri, Ashby, from that species were dealt with, as the valves 

 were not disarticulated. It has now been possible to ex- 

 amine disarticulated specimens of both species. The sinus 

 or space separating the sutural laminag in the median valves 

 is very broad, with a deep slit at each side, this slit pene- 

 trating to the tegmentum, having a spade-like process, with 

 a denticulate margin, between the two slits. This feature 

 is present in both the two living species, but in the fossil 

 one under review these slits are either entirely absent or 

 rudimentary. It suggests that this feature may have been 

 developed in recent times, in which case the fossil Loricella 

 might very properly receive sub-generic distinction. 



The examination of separated valves for the purposes 

 of this paper has revealed a further difference between L. 

 angasi and L. torri. 



While the latter has, especially in the anterior valve, 

 sharply serrated and deeply propped and cut teeth, the 

 teeth in the former L. angasi, as compared with it, are com- 

 paratively blunt, and the propping much less finely cut. The 

 fossil species under review seems more closely to approach 

 L. angasi in this respect. 



Note. — Carpenter MS. is quoted by Pilsbry (Man. Con. 

 Vol. XIV., 239) as follows, referring to L. angasi, Ad. and 

 Ang.: — *'The sutural plates separated, but having a lamina 

 "between them, which is sometimes bilobate or denticulate," 

 and again, "the sinus having a separate lamina, somewhat 

 "lobed." The figure 11, pi. 51, in same volume, does not at 

 all represent this character as it really is, I have there- 

 fore photographed a median valve of that species showing 

 this spade-like process, which separates the sutural laminae, 

 and I also figure a photograph of the anterior valve of both 

 species showing the serrated teeth, which are in both strongly 



