548 PROFESSOR E. RAY LANKESTER. 
entosternites of Limulus and other Arachnida. It agrees 
with these only so far as that it is a free internal skeletal 
iece. 
4 In the abdominal region of Limulus small loose fibro- 
cartilages, similar in nature to the Entosternite, are found, 
connected with the tendons of muscles. I have isolated 
four such pieces. They are mentioned by Straus Durkheim. 
(To be continued.) 
