318 MYOLOGY OF CHLAMYDOSAURUS KINGII, 



Internal oblique. — Lines almost the entire chest ; rising from all 

 the vertebral, and inserted into all the sternal ribs by digitations, 

 and into the rectus by continuity. 



Transver sails. — From a fascia extending from the pelvis to the 

 ribs ; from this long origin it runs to be inserted into the rectus 

 and sternum. 



Inter cost ales externi. — Run obliquely between all the ribs both 

 vertebral and sternal. 



Intercostales interni — Between the sternal ribs only : but on the 

 upper half of the vertebral ribs the deep fibres of the extemi are 

 more or less separable as an internal layer 



Retrahentes costarum from the ventral surface of the vetebrre 

 adjacent to the head of each rib forwards to the fourth. The 

 broad and delicate posterior digitations pass beneath two ribs to be 

 inserted into the third in advance, The first two are more distiuct, 

 especially the first which rises at the fourth rib, and is inserted by 

 a rather long tendon into the second. 



Caudalis (Plate xvi., figs. 12 & 13 — f.c.) — Consists of four rows 

 of cone-in-cone muscles, one on each side of the upper and lower 

 surfaces. Posteriorly these columns occupy the spaces between the 

 spines and hsemapophyses and transverse processes. Towards the 

 base of the tail the columns separate from the vetebrse and form an 

 investing layer over the origins of the piriformis, femorcaudal and 

 compressor cloacse. The upper lateral column is an extension 

 backwards of the longissimus dorsi. The upper median is a 

 similar extension of the sacrolumbalis, but it has also a special 

 origin by tendon from the spine of the ilium. From this origin a 

 long round fascicle enclosed in a sheath formed of the rest of the 

 muscle beneath runs backward to a point at the eleventh caudal 

 vertebra. The lower median rises in conjunction with the lower 

 lateral from the transverse processes of the first and succeeding 

 caudal vetebrse. Expanding, they join their fellows of the opposite 

 side on the basal median line, overlapping as they descend the 

 origin of the pyriformis. By their separation they form the lower 

 median and the lower lateral columns. 



