310 



The tubes of the fringe and the holes in the disk are of the same 

 diameter ; and the holes in the disk are all more or less tubular. 



The valves of the nucleus are very distinct, and uniform in shape 

 and size, in all the specimens. They are oblong, with the apex ra- 

 ther behind the middle of the shell ; and the hinder end is obliquely 

 truncated. They resemble in form the outline of Thracia declivis. 



They differ among themselves in the following particulars : — 1. 

 In the size and form of the exposed part of the valves, some having 

 this part much shorter from back to front, and broader from side 

 to side, than others. In one the valves are even longer than broad. 

 2. In the number and in the distance between the "ruffles" at the 

 siphonal end, this peculiarity producing the chief difference in the 

 length of the specimens. In general the base of the plaited part of 

 the ruffle commences a little above the apex of the expanded part 

 of the former ruffle ; and of the nine shells agreeing in this parti- 

 cular, one has 3, three 4, two 5, two 6, and one 8 ruffles. 



In one specimen which has four ruffles, which are not so much 

 expanded as the average in the other examples, there is a consider- 

 able space between them, and the space increases in length as they 

 are formed, so that the tube of the shell is much elongated ; but one 

 specimen is intermediate in the length of the interspaces and in the 

 more expanded form of the ruffles. 



M. Chenu, in his Monograph, considers a specimen with elongated 

 interspaces between the ruffles a different species, under the name of 

 A. Detessertianum. 



One specimen has a much more slender, rather tapering, shorter 

 tube than the rest ; and it is evident that this specimen has been 

 broken off at the apex, and a new series of ruffles have been formed 

 on the broken apex : the first or lowest ruffle is irregular in form, 

 to adapt itself to the broken edge; the rest are regular ; and they are 

 all closer together than usual. 



2. Warnea australis. B.M. 



Asp. austral 'e, Chenu, t. 3. f. 1. 



A. incertum, Chenu, t. 4. f. 6, a fragment. 



A. Cumingianum, Chenu, t. 3. f. 4, variety? 



Australia, Swan River. 



Aspergillum incertum, Chenu, t. 4. f. 5, is probably the same as 

 A. australe, as it is said (but on what authority I know not) to come 

 from the same locality; but it is so distorted by the stones in the 

 sand in which it lived, as to render it almost impossible to determine 

 it with certainty. This specimen has been broken in the middle of 

 the tube when the animal was alive ; and it has been repaired by the 

 animal, part of the broken part of the tube forming a kind of sheath 

 to the repaired portion. 



The specimens of Aspergillum Cumingianum in Mr. Cuming's 

 collection appears to be only a very distorted specimen of Warnea 

 vaginifera or W. australis, without any marginal fringe. The tube 

 is very irregular, with scattered moderate-sizetl stones and impressed 

 grooves in every direction, as if it had lived where the animal must 



