PLATE 11. 



Fig. 



1. The brachial aponeurosis and spiral arms of Terehratula Jlavescens, showing the 



central part of the nervous system, with the brachial and beginning of the 

 palhal nerves. Magnified 6 diameters. 



2. The peduncle and a large proportion of the soft parts of Terehratula flavescens. 



showing the principal ramifications of the pallial nerves or the dorso-pallial fold 

 of the mantle. Magnified 12 diameters. 



3. Some of the soft parts of Lingula anatina, exposed by the removal of the valve and 



pallial lobe, answering to the ventral ones in Terehratula, and of the digestive 

 organs, chiefly to show the trunks of the visceral and muscular nerves. 

 Magnified 4 diameters. 



3^ 



