ischinm posteriorly united with its fellow into one mass; pubis or 

 part wedged in between the ilium and ischium and united with its 

 fellow on the ventral line. 



b. Bones of the free-limb. ( i ) In the thigh one long bone, the 

 femur. (2) In the crus or leg, the tibio- fibula representing a fused 

 tibia and fibula. When the leg is extended as the arm was, the 

 anterior side is the tibia! side. (3) Tarsus: this is made up chiefly 

 of two long proximal bones fused at the ends and representing a 

 tibialc (or astragalus} and a fibulare (or calcancum). Between these 

 and the digits are three small distal tarsalia, the inner or anterior 

 one articulates with digit i, the flat larger outer one with 2 and 3 and 

 (as a cartilaginous continuation) with 4 and 5. 



c. Digits. There are five, each with a metatarsal and three pha- 

 langes, except the first or tibial digit which has two phalanges, (i) 

 The hard cushion on the inner side of the sole is supported by what 

 seems an additional inner or tibial digit, represented by three short 

 bones articulating with the same inner tarsalium that digit i does. 



Draw and label the bones of the pelvic girdle and leg. 



V. THE SKULL. 



a. In the dry skull note the following parts and draw the whole 

 on a large scale, as seen from above, (i) The cranium or brain- 

 case. (2) The sense-capsules, auditory and olfactory. (3) The 

 facial bones separated more or less widely from the cranium. (4) 

 The foramen magnum, or passage from the neural canal into the 

 cranium. (5) The convex condyle on each side of the foramen 

 magnum corresponding to the two parts of the atlas. These are 

 upon the e.voccipitals. (6) Pro-otics or bones anterior to the exoc- 

 cipitals, forming on each side the roof and anterior wall of the 

 auditory capsule. (7) The squamosal, a hammer-shaped bone, run- 

 ning from the pro-otic downward and posteriorly towards the articu- 

 lation of the lower jaws. (8) The fronto-parietals: two long parallel 

 bones in the roof of the cranium with a median suture between them. 

 (9) Nasals: immediately anterior to the latter and triangular in out- 

 line. (10) Pre-ma.rillae : between the nasals and the gape anteriorly, 

 (n) Ma.riUae: extending from the latter bone on each side along 

 nearly all the upper edge of the gape. (12) Quadrato-jugal: a deli- 

 cate bone forming the boundary of the gape between the maxilla 

 and squamosal on each side. 



b. On the ventral surface note and draw the following: (i) 

 Parasphenoid: a dagger-shaped bone, running along the floor of the 

 cranium or roof of the mouth. (2) Sphcnethmoid or girdle bone : 



65 



