352 MISS E. J. BECK ON THE MUSCULAR 



the preoial entosclerite, and runs straight up, being attached to the carapace near the 

 median line (one on each side). It has been mentioned before amongst the dorso- 

 ventral muscles. 



The anterior latero-dorsal preo7-al entosclerite muscle (93) is attached to the anterior 

 part of the preoral entosclerite. It runs underneath the coxal entosclerite of the first 

 appendage, and is attached to the lateral part of the carapace. 



The median latero-dorsal preoral entosclerite muscle (94) is attached to the posterior 

 process of the preoral entosclerite, and runs laterally to the carapace, to which it is 

 attached. 



The posterior latero-dorsal preoral entosclerite muscle (95) is attached to the posterior 

 part of the posterior process of the preoral entosclerite, and runs laterally to the cara- 

 pace, to which it is attached. 



The anterior Ji.rst-coxal-entosclerite preoral-entosclerite muscle (96) is a broad muscle 

 attached to the interior surface of the posterior process of the preoral entosclerite and 

 to the interior surface of the first coxal entosclerite. 



The x^osterior Jirst-coxal-entosclerite preoral-entosclerite muscle (97) is a small muscle 

 attached to the posterior end of the posterior process of the preoral entosclerite and to 

 the posterior portion of the first coxal entosclerite. 



The anterior preoral entosclerite pharyngeal muscle (98) (PI. LXXIX. fig. 12) is a 

 small muscle attached to the interior surface of the anterior portion of the preoral 

 entosclerite, and runs down to the pharynx, to which it is attached on its superior 

 surface. 



The posterior preoral entosclerite pharyngeal micscle (99) (PL LXXIX. fig. 11) is a 

 larger muscle, attached to the interior surface of the preoral entosclerite. It runs 

 horizontally towards the similar muscle of the other side, and is attached to the lateral 

 walls of the pharynx. 



VI. Muscles to the Appendages. 



Prosonia. — The muscles belonging to the appendages of the prosoma are of two 

 kinds, intrinsic and extrinsic. 



Intrinsic Muscles. — Of the intrinsic muscles, I shall only speak of those which run 

 inwards from the appendages, and are attached internally to the coxal entosclerite or 

 to the interior margin of the coxal sclerite. In speaking of the interior margin of the 

 coxal and deutomerite sclerites I refer to that margin nearest to the body of the 

 animal. 



The exterior Jirst-coxal entosclerite-deutomerite muscle (100) is a broad muscle attached 

 posteriorly to the exterior margin of the coxal entosclerite and anteriorly to the interior 

 margin of the deutomerite sclerite of the first appendage. 



The interior Jirst-coxal entosclerite-deutomerite muscle (101) is a narrow muscle 



