1890.] HELODERMA SUSPECTUM. 181 



and fleshy, although laterally compressed, and at first passing 

 directly forwards, soon turns outwards, and becoming tendinous is 

 inserted into the trochanter major of the femur of the same side. 

 Before arriving at this insertion, the femoro-caudal throws off 

 another tendon, which, passing down through certain other muscles 

 of the thigh, is inserted into the hinder surface of the interarticular 

 cartilage between the tibia and the femur. Professor Mivart found 

 this second tendon of insertion likewise present in Iguana. 



70. The Ischio-caudal muscle arises from the outer aspect of the 

 chevron-bone of the eleventh caudal vertebra, counting from the 

 sacrum, and, ensheathed in the fat that is surrounded by the 

 infero-candal of the same side, it passes directly forwards, as a sub- 

 cylindrical, muscular cord of some size; running close to the 

 vertebrae, it becomes bulbous just before arriving at the vent, and 

 dipping down, and passing forward between the two layers of the 

 c/o«ca^ muscle, is finally inserted into the tuberosity of the ischium. 



71. Cloacal muscle. — This arises, almost carneous, from the 

 ventral surfaces of the diapophyses of the fourth and fifth caudal 

 vertebrte, and passing downwards and forwards as a moderately thin 

 sheet of muscle it becomes inserted along upon the upper surface of 

 the cloaca from its posterior lip forwards. As already stated above, 

 the ischio-caudal passes between its layers on its way to its insertion. 

 This cloacal muscle is situated to the outer side of \Aie femoro-caudal, 

 and internal to the infra-caudal. 



72. Transversus perinei. — Superficial to all the muscles here 

 described, and stretching transversely across the region just posterior 

 to the cloaca, we find a thin muscular layer faintly divided into two 

 by a median, longitudinal line. Either la'teral half of this represents 

 one of the present muscles, a transversus perinei. For the most 

 part it is attached to the post-cloacal fascia of the region in question. 



(From this point onwards we resume our descriptions of the 

 muscles of the trunk.) 



73. Rectus abdominis.— Arising from the xiphoidal extremity of 

 the sternum, and from the costal rib that there articulates, either 

 rectus abdominis passes down the entire length of the body to the 

 anterior pelvic region, being throughout" its course intimately 

 united with its fellow of the opposite side. Posteriorly it becomes 

 inserted into the ischio-pubic ligament and the neighbouring fascia. 



74. Pyramidalis. — This muscle is formed by a strong triano'ular 

 slip thrown off by the rectus abdominis just above the insertion of 

 the latter. Its fibres converge, and passing outwards and slightly 

 backwards they are inserted, upon either side, iuto the"hamular 

 process " of the pubis. Sanders found this muscle present in 

 Liolepis, but he does not award it a separate description (P. Z. S 

 1872, p. 161). 



75. Obliguus abdominis externus. — This broad and powerful 

 sheet of muscle here arises by an anterior expansion from the inner 

 surface of the skin overlying the chest ; by means of strong digita- 

 tions from all of the dorsal ribs, and from six or seven of the 

 abdominal ribs that follow them ; and, finally, by far less distinctly 



