354 MISS E. J. BECK ON THE MUSCULAK 



median line. It runs laterally to the exterior portion of the interior margin of the 

 coxal sclerite of the first appendage. 



The interior first dorso-coxal muscle (110) is a large muscle, the larger part of which 

 is attached posteriorly, the smaller part more laterally, to the carapace ; these are united 

 in a common origin at the interior portion of the interior margin of the coxal sclerite 

 of the first appendage. 



The superior first dorso-coxal muscle (111) is attached posteriorly to the carapace. 

 It is a narrow muscle, running underneath the larger part of the last-mentioned 

 muscle, and is attached anteriorly to the superior portion of the coxal sclerite of the 

 first appendage. 



The anterior second dorso-coxal muscle (112) is a thick muscle attached posteriorly 

 to the carapace, and running forward to the antero-lateral portion of the interior 

 margin of the second coxal sclerite. 



The posterior second dorso-coxal muscle (113) is attached to the carapace towards its 

 lateral portion and to the postero-lateral portion of the interior margin of the second 

 coxal sclerite. 



The third dorso-coxal muscle (114) is attached to the lateral portion of the carapace 

 and to the antero-lateral portion of the interior margin of the third coxal sclerite. 



The fourth dorso-coxal muscle (115) is attached to the lateral portion of the carapace 

 and to the antero-lateral portion of the interior margin of the fourth coxal sclerite. 



The anterior fifth dorso-coxal muscle (116) is attached to the carapace near the 

 median line, at its posterior portion, and to the antero-lateral portion of the interior 

 margin of the fifth coxal sclerite. 



The posterior fifth dorso-coxal muscle (117) is attached to the lateral portion of the 

 carapace and to the postero-lateral portion of the interior margin of the fifth coxal 

 sclerite. 



The anterior sixth dorso-coxal muscle (118) is attached to the posterior portion of 

 the carapace near the median line and to the antero-lateral portion of the interior 

 margin of the sixth coxal sclerite. 



The posterior sixth dorso-coxal muscle (119) is attached to the lateral portion of the 

 carapace and to the postero-lateral portion of the interior margin of the sixth coxal 

 sclerite. 



Coxal Entosclerite Muscles. — The extrinsic muscles of the coxal entosclerites are 

 attached to the plastron and to the carapace. Those running from the plastron are 

 attached to the posterior surfaces of the third and fourth posterior coxal entosclerites, 

 and have been mentioned under the muscles attached to the plastron (74, 78). 



There are four muscles from the carapace to the coxal entosclerites, two of which 

 are attached to that of the first appendage, and one to each of the posterior coxal 

 entosclerites of the third and fourth appendages. 



The lateral first dorso-coxal entosclerite muscle (120) is attached to the lateral portion 



