ANATOMY OF THE LEMUROIDEA. 95 
Group V. Lemur and Galago. 
We have found the palmar lumbricales to be four in number in the genus Lemur 
and in Galago crassicaudatus. 
Group VI. Lemur and Perodicticus. 
These widely different forms approach each other in having each two supracostal 
muscular slips. 
Group VII. Galago, Cheiromys, Nycticebus, and Perodicticus. 
1. All the genera in this group, excepting G. crassicaudatus, have but three lumbrical 
muscles in the hand. 
2. Excluding Perodicticus, they have but a single supracostal slip. 
Group VIII. Galago and Tarsius. 
1. These agree in the occipito-frontalis and the retractor muscles of the ear being 
unusually well developed. The retrahens aurem is indeed compound in them, where it 
may be assumed a certain correlation of structure and growth exists in connexion with 
the remarkable folding movements of their capacious concha. 
2. They alone of all the Lemuroidea dissected show a depressor scapule muscle. 
3. In them the flexor profundus digitorum has three muscular bellies, whereas in the 
other genera they are more or less united. 
4. In the two genera of this group the flexor longus hallucis has origin from the 
fibula only. 
Group IX. Galago and Loris. 
1. The iliacus appears only to be double in them alone ; but the difficulty of separating 
the fibres of this usually single muscle renders their singularity in this respect doubtful. 
Galago certainly has a vertebral besides its iliac origin. 
2. They, as well as Lemur xanthomystaz, have a clearly double extensor indicis. 
Group X. Galago and Perodicticus. 
The myological agreement between these two genera consists in the extensor longus 
digitorum being single-bellied and divisible into three main tendons going to the cor- 
responding digits. 
Group XI. Loris and Nycticebus. 
1. The biceps of the arm is a single muscle in these two Indian genera, but double, 
as before noticed, in all kindred forms. 
2. In Loris and Nycticebus, and in them only of all the Lemuroidea, the flexor 
