32 Mammalia. Quadntmana. 



In the Leynuridre the cervical vertebrae are generally broad and short, and 

 their neural arch is low and flat, and sometimes fissured behind (Indri). The cen- 

 tra of the dnrsal vertebriE of the Cheiromys (Aye- Aye) are carinate ; the neural 

 spines are commonly all of equal strength, In the true Lemurs eight pair of 

 ribs join the sternum, which consists of seven bones and an ensifoim cartilage. 



The Scapular Arch and Appendages. The anterior pair of limbs 

 aid in support and locomotion. Clavicles are always complete. Tlie 

 Coracoid process of the scapula is usuallj' large and long. The 

 Elhoiv joint allows of both rotatory and flexile movcmonts of hand 

 and fore-arm. Most Quadrumana have the innermost digit opposable, 

 i.e. have a ^ rue 2yollex, or thumb. 



Cntarrhina. The curves of the chvicles are usually not well mai'ked : these 

 bones are of excessive length in the " Long-armed" Apes. The humerus is 

 seldom perforated even slightly at its distal extremity : the condyloid processes 

 are considerably developed. The peculiar length of ai*m in the "Long-armed" 

 Apes {e.f/. Siamang, Hylobates) is chiefly due to the unusual length of the anti- 

 brachial bones. All Catarrhina have a true pollex, except Colobus. 



PlatyrrJiina. In Ateles (Spider Monkey) the long and large coracoid has an 

 angular tuberosity, which sometimes joins the anterior costa. so as to circum- 

 scribe the prescapular notch. The humerus is in this group seldom perforated, 

 either above or between the condyles. 



LemnridcB. In Lichanotus (Indri) the coracoid is especially large and strong. 

 The humerus is usually perforated above the inner condyle : when bent upon 

 the chest the humerus reaches to the tenth rib : this length is characteristic in 

 this Sub- order. In Cheiromys the middle metacarpal is remarkable for its 

 extension, and sudden contraction in size towards the distal extremity. The 

 fourth digit is always the longest in this Sub order, except in Cheiromys, in 

 which the phalanges of digit iii. are attenuated to form the hooked probe- 

 like finger. 



The Peine Arch and Appendages. The Pelvis is long and narrow. 

 The Iliac bones are long, more or less flat, slender, and extended 

 (except in the highest Api's) in a continuous line with the sacrum. 

 The Ischia are in a line with the ilia. The Acetahula have a tendency 

 to face forwards, and towards each other. The Femur has usually 

 a short neck, is itself short, and so articulated with the leg bones as 

 to retain habitually a ben I position of the knee : the great trochanter 

 usually rises to the height of the bead of the femur. The innermost 

 digit of the posterior pair of limbs is always opposable, i.e. in a 

 thumb-like condition, as in the hands ; hence the name of the Order, 

 QnadTu-mana. 



Catarrhina. The posterior angle or spine of the ilium is above the sacral 

 surface, not behind it (as in Man). In all that have dermal callosities, the 

 ischia are expanded into rough flattened tuberosities. There is no oblique 



