890 MB. F. o, picKARD cambetdgb ois [Nov. 29 



former supplying all four toes, the latter passing deep to supply 

 the muscles. The external popliteal nerve divides into musculo- 

 cutaneous, which runs down among the peroneals to the dorsum 

 of the foot, and the anterior tibial, which breaks up into twigs for 

 the extensor muscles of the leg, one fine branch descending to 

 supply the extensor brevis digitorum muscle. 



The small sciatic, internal pudic, and inferior gluteal nerve come 

 from the 1st and 2nd sacral nerves ; they have practically the 

 human distribution. The 3rd, 4th, 5th, and 6th nerves form a 

 long cord which runs along the side of the tail. 



Summary of Points of Interest. 



l.^edetes possesses only two pairs of teats, showing that it is 

 not in the habit of bringing forth manj'^ young at a birth ; the 

 presence of only one foetus in the uterus confirms this. 



2. The upper incisors of Pedetes are smooth, those of Dipus are 

 grooved, but the embryo of Pedetes also has grooved incisors. 



3. The presence of the nail in the palm of Pedetes, described by 

 Bardeleben, is confirmed. 



4. Bardeleben's description of the radial ossicle or prepollex 

 exactly describes this specimen ; in the foetus the radial ossicle is a 

 definite cartilaginous structure. 



5. In the foot a structure apparently serially homologous with 

 the radial ossicle was found ; but it was attached to the distal 

 instead of to the proximal row of tarsal bones. 



6. The trachea was divided into two by a vertical septum. 



7. There was no gall-bladder. 



8. A study of the muscles showed that Pedetes was allied to the 

 DipodidsB, but had more hystricomorphine tendencies than those 

 animals. 



3. On new Species of Spiders from Trinidad, West Indies. 

 By Frederick O. Pickard Cambridge, B.A. 



[Eeeeived October 18, 1898.] 

 (Plate LIV.) 



In this communication I propose to give descriptions of three 

 new species of Spiders based on specimens collected by Dr. Walter 

 Ince and Mr. Thos. Potter, of Port-of-Spain, Trinidad, and of 

 one new species of which specimens are in the collection of the 

 British Museum from the same locality. 



The total number of species of Spiders from this island now re- 

 presented in the British Museum amounts to eleven only, so that 

 our friends who have been good enough to supply us with material 

 will perceive that further consignments from that locality will be 

 much appreciated. 



The examination of Dr. luce's collection has led to a very 



