Dr. F. A. Bather — Tube-building Fossil Annelides. 485 



There is slight variation in the character and arrangement of the 

 leaflets that compose these tubes. Thus in A 1568 (Fig. 8) the leaflets 

 have a length of 20 mm. or a little less, and cross one another irregularly, 

 but are more or less longitudinally placed ; in A 1569 the leaflets are 

 14 mm. or less in length, and cross irregularly; in A 1570 they are 

 about 10 mm. long, irregular, but tend to a longitudinal arrangement ; 

 in A 1640 they are 10 mm. or less in length and quite irregularly 

 scattered; in A 1565 they are rather shorter and irregular, and are 

 combined with fragments of bark ; in A 1567 the leaflets lie somewhat 

 longitudinally or at a rather regular angle, and there is in places an 

 appearance as of two layers crossing ; in A 1566 (Fig. 7) the leaflets are 

 short, probably mixed with bark, and seem to imbricate irregularly. 



These tubes have a rather straighter appearance than those of fish- 

 debris; but this may be due to their less length. A slight curve is 

 to be seen in A 1566, which is 10 cm. long. A 1640 is probably 

 curved, but is much flattened, and its outlines are not clear. 



As Dr. Stopes has kindly pointed out to me, J. Velenovsky in 1885 

 figured fir-needles composing a similar tube in the Cretaceous Teplitz 

 beds of Raudnic, Bohemia, and gave to them the name Abies minor. 1 

 It is not to be inferred that any of our specimens necessarily belong 

 to the same species of worm as the tube figured by Yelenovsky, or 

 that the plant-remains are identical with those described by him. 



Tubes of Echinoderh-debris. 



At present I know of only the one specimen previously referred to, 

 namely A 1583 in the British Museum. This is composed of ossicles 

 of Asteroids and Ophiurids. It comes from the Cenomanian Grey 

 Chalk of Folkestone, Kent. Its length is 15 cm. ; its width, 16 mm. 



Tubes of this composition may be of more frequent occurrence 

 than one might infer from their rarity in our collections. Assemblages 

 of small Echinoderm ossicles do not, as a rule, appeal to the collector, 

 unless the ossicles in themselves have some peculiar interest. 



The Taxonomic Value of the Building Material. 



Before proceeding to the discussion of those tubes in which no 

 building material is obvious, we may pause to consider whether the 

 difference of composition in the tubes already described indicates 

 the existence of more than one species of Annelid. It may be that 

 the worm merely seized on any appropriate fragment that chanced to 

 lie in its neighbourhood ; or it may be that divers species selected 

 each its own peculiar objects, as is the habit of various lowly animals 

 in modern seas. 2 Either view may be supported by the described 

 habits of modern Terebelliformia. 



The process of tube-construction in Terebella and its allies was 

 observed and described by Sir J. G. Dalyell (1853, Poivers of the 

 Creator, vol. ii, pp. 176-205), and Mr. Arnold T. AVatson has given 



1 Die Gymnospermen der bohmischen Kreideformatlon, Prag, 1885 ; see 

 p. 33, pi. viii, fig. 1. 



2 e.g. Phorus agglutinans covers its shell with extraneous objects ; one form 

 carefully using rocks is called ' the mineralogist ' , another selecting small shells 

 is called, 'the conchologist ' : this supposed selection may, after all, be due to 

 the occurrence of shells in one locality and stones in another. — Editor. 



