26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 92 



midline of the body. It passes forward and slightly outward to its 

 tendinous insertion on the tough membrane composing the dorsal sur- 

 face of the coxopodite. It causes the coxopodite, and with it to some 

 extent the inner part of the whole appendage, to be brought upward 

 and inward. 



J I. Musculus promotor lateralis I pedis maxillaris (fig. 9). — This 

 muscle is hidden partly beneath the first of the attractors of the epipo- 

 dite and partly by the fused lamellae of the first and second thoracic 

 paraphragms, on the outer ventral surface of which it arises. It runs 



70 73a 



Fig. 9. — The first maxilliped. 



JO, musculus promotor medialis I pedis maxillaris ; 71, musculus promotor 

 lateralis I pedis maxillaris; 72, unnamed muscle; 73a-b, musculus attractor epi- 

 poditis I pedis maxillaris ; 74, unnamed muscle ; 75, unnamed muscle ; 76, unnamed 

 muscle ; 77, musculus adductor exopoditis I pedis maxillaris ; 78, musculus ab- 

 ductor flagelli exopoditis I pedis maxillaris ; 79, musculus flagellaris exopoditis 

 I pedis maxillaris. 



Cndi and Cndi, first and second endites of the coxopodite; Cxpd, coxopodite; 

 Endpd, endopodite ; Eppd, epipodite ; Expd, exopodite. 



forward and slightly inward to its attachment on the lateral border of 

 the coxopodite just at the point of origin of the epipodite. It helps to 

 raise the appendage but otherwise opposes the medial promotor by 

 exerting an outward pull. 



^2. (Fig. 9).^ — -This powerful but short muscle originates on the 

 endosternite, passing outward beneath the median promotor to its 

 insertion on the extreme outer ventral borders of the coxopodite with- 

 out a tendon. It is not feasible to attempt to name this muscle func- 

 tionally, as no definite movement of the appendage can be assigned 

 solely to it. It appears to lie in approximately the same position as does 

 the levator muscle in Astaciis. 



