NO. 9 



MUSCULATURE OF THE BLUE CRAB COCHRAN 



63 



is directly behind the posterior termination of the zygocardiac ossicle, 

 to which it is closely articulated, and its inner upper border is the point 

 of insertion for the outer cardiopyloric muscle {210 a). Inwardly, 

 the ossicles project as small triangular plates lying below the median 

 tooth of the urocardiac ossicle. (Figs. 25 A, B, 26, 27.) 



V. Urocardiac ossicle. Single. — This ossicle is a broad, shield- 

 shaped median plate which is almost completely fused with the meso- 

 cardiac ossicle on its anterior border. It projects backward and finally 



CdAl 

 CdPl 



VIII X XI XIII XX/XXI Amp 

 XVI 



Fig. 26. — Lateral view of stomach showing ossicles after removal of all muscles. 



Ill, zygocardiac ossicle ; IV, exopyloric ossicle ; VI, propyloric ossicle ; VII, 

 pyloric ossicle ; VIII, pectineal ossicle ; IX, prepectineal ossicle ; X, postpectineal 

 ossicle; XI, inferolateral cardiac ossicle; XII, subdentary ossicle; XIII, lateral 

 cardiopyloric ossicle; XIV, anterior mesopyloric ossicle; XV, posterior meso- 

 pyloric ossicle; XVI, uropyloric ossicle; XVIII, pre-ampullary ossicle; XX, 

 anterior supra-ampullary ossicle; XXI, middle supra-ampullary ossicle; XXII, 

 posterior supra-ampullary ossicle; XXIII, anterior pleuropyloric ossicle; XXIV, 

 middle pleuropyloric ossicle. 



Amp, ampulla; CdAl, anterolateral cardiac plate; CdPl, posterolateral cardiac 

 plate; Oe, esophagus. 



downward as an elongate, heavy plate, articulating with the inner 

 termination of the propyloric ossicle. On its ventral (inner) surface 

 it bears the heavy, ridged median tooth which opposes the lateral teeth 

 of the zygocardiac ossicles. (Figs. 25 A, 27, 28.) 



VI. Propyloric ossicle. Single. — This appears externally as a small, 

 curved, median ossicle lying in the dorsal wall of the stomach, its 

 outer end just behind the inner terminations of the exopyloric ossicles 

 and articulating closely with them by a short bar of cartilagelike tissue. 

 Upon dissection, the inner part of this ossicle appears triangular in 

 shape, its inner point meeting the uropyloric ossicle at its posterior end 

 5 



