96 LIVERPOOL BIOLOGICAL SOCIETY. 
bibliography, which, although it does not pretend to be 
exhaustive, mentions apparently all the more important 
works; references to all important papers may also be 
found in Davidson’s ‘‘Monograph of the Brachiopoda,”’ 
now being published.* 
When I first saw M. Joubin’s paper, I felt that it was 
almost impossible but that he had more than covered the 
observations on Crania and Lingula which I had been 
making recently; but slight differences in method are 
often sufficient to bring histological details to light, and it 
is only on such points of detail that I can claim to carry 
on the work of my predecessors just one step farther. 
Considering the work which has already been done in 
that field, it will not be necessary, I think, to go into 
anatomical minutis further than is needful for the under- 
standing of the special remarks which I have to make. 
I may state that the method followed throughout has 
been simply to decalcify the specimens, to stain with 
either alum carmine or with picro-carmine, and to sec- 
tionize the whole animal. The results of staining with 
picro-carmine have been decidedly more satisfactory than 
those obtained with alum carmine, the tissues as a whole 
appear clearer and the differentiation is more complete. 
The sections made have been both longitudinal and 
transverse. 
GENERAL ANATOMY. 
In Craua and Lingula the soft tissues are completely 
enclosed between a pair of shell valves, placed dorsally 
and ventrally (see Pl. III., fig. 1); in Crana the animal is 
attached to foreign bodies by the whole surface of the 
ventral valve, in Lingula by a stalk (Pl. IV., fig. 4). The 
shell in both is lined with and secreted by the mantle with 
* Vol. vi., Paleeontographical Society, London, 1886, 
