390 



ZOOLOGY 



Behind the prosoma, the body is covered in by an abdominal 

 carapace, the anterior part of which shows dorsally faint traces 

 of being composed of seven segments. This region corresponds 

 with the mesosoma of other forms ; behind it the metasoma pre- 



FiG. 222. — Under side of Limulus polyphemus, Latr., 9 • 



C. Carapace. 

 Th. Atdomen ( = meso- and meta-soma). 

 T. Telson or spine. 



2. Chelicerae. 



3. Pedipalps. 



3a'. Detached pedipalps of i . 

 4-7. Thoracic walking-legs. 



8. Lamellae with genital openings. 

 9-13. Branchiferous lamellae. 

 m. Mouth. 



sents a smooth unsegmented surface. The anus is situated at the 

 end of the metasoma, and a long pointed spine extends behind it. 



Appendages of Limulus. 



1. Chelicerae. 



2. Leg-like appendages (pedipalpi). 



7. Plates with genital pores. 



8. ,, ,, branchiae. 



10. 

 11. 

 12. 



The appendages which are found on the ventral surface of 

 the body commence with a small three-jointed pair of chelicerae, 

 placed one on each side of the upper lip, which overhangs the 

 mouth. The next five pairs of appendages are leg-like, and 

 are arranged round the mouth; they consist of six joints — the 

 proximal one or coxa is enlarged, and its anterior border is 



