NO. 9 



MUSCULATURE OF THE BLUE CRAB COCHRAN 



23 



^y. Muscitlus prouiotor II maxillae (fig. 8). — -This long, cylindrical 

 muscle originates on the dorsal surface of the endopleurite of the last 

 head segment, which segment coalesces with the first two thoracic seg- 

 ments. It runs straight forward to its insertion on the skeletal ridge 

 that borders the proximal part of the coxopodite. It brings the cox- 

 opodite backward and upward, at the same time causing a similar 

 movement in the attached anterior part of the scaphognathite. 



58. Musculus remotor II maxillae (fig. 8). — Almost hidden by the 

 respiratory muscles, the remotor arises on the dorsal surface of the 

 endosternite of the same segment just in front of the apodemal fora- 



G4 G3 



Endpd 



'Cnd2 



Fig. 8. — The second maxilla. 



Sy, musculus promoter II maxillae; 58, musculus remotor II maxillae; 59, 

 musculus depressor II maxillae; 60, musculus adductor coxopoditis II maxillae; 

 61, musculus adductor endopoditis II maxillae; 62, musculus flexor scaphogna- 

 thitis II maxillae; 6^^-6g, musculi respiratorii II maxillae. 



Cndi and Cnd-2, first and second endites of the coxopodite ; Endpd, endopodite ; 

 Scg, scaphognathite. 



men, and passes forward and outward between respiratory muscles one 

 and two to its insertion on the thickened edge of the coxopodite slightly 

 lateral to and below that of the promotor. It brings the coxopodite up- 

 ward and somewhat toward the center. 



5Q. Musculus depressor II maxillae (fig. 8). — -This is the smallest 

 and weakest muscle in the entire appendage. It arises ventrally on the 

 endosternite, appearing as two very thin branches which travel for- 

 ward through the coxopodite to their insertion on its proximal border. 

 It causes the coxopodite to move downward and inward. In Asfacits 

 this muscle also has two branches. 



60. Musculus adductor coxopoditis II maxillae (fig. 8) . — This rela- 

 tively short and slender but strong muscle arises on the inner anterior 



