LÖNNBERG, ON A NEW ORYCTEROPUS FROM NORTHERN CONGO. 17 



then decrease again a little on the 3 last. They are directed 

 a little forward, b ut not much. The anterior ones are broad 

 from base to tip, the posterior ones are narrowed towards 

 the tip. The metapophyses have the same situation as in 

 the last thoracal vertebrse but are a little more erect. They 

 are larger than those of the posterior thoracal region and 

 subequal inter se on the six anterior lumbar vertebrae but 

 much smaller on the last, The anapophyses decrease, although 

 irregularly, from the first to the fifth lumbar vertebrse but 

 are entirely missing on the two last. The processus transversi 

 increase from the first (30 mm. long, 15 mm broad) to the 

 sixth, which is very large and expanded (f32 mm. long, 40 

 mm. broad). The seventh is again smaller. The processus 

 transversi of the three posterior lumbar are so greatly widened 

 that they almost touch each other. 



The 6 sacral vertebrse are completely soldered together. 

 Their neural spines are also completely fused together so as 

 to form a continuous crest only broken by one roundish 

 foramen between the last and next last neural spine. This 

 crest is only a little higher posteriorly, being already on tlie 

 first sacral vertebra 25 mm. The appearance of the '^acrum 

 of O. erikssoni is thus rather different from that in O. ajer 

 where the coalescence of the vertebrae is less complete and 

 the neural crest quite low anteriorly. In the latter the meta- 

 pophyses are only visible on the anterior sacral vertebrae but 

 in O. erikssoni on all six, being lowest on the fourth and 

 then increasing again to the 6th. The broad plate formed 

 by the transverse processes of the three posterior sacral ver- 

 tebrae measures behind, where it is widest, 133 mm. across. 



The transverse processes of the three anterior caudal 

 vertebrae are very large, measuring 5 ^l-> to 6 cm. in length 

 and 37 to 45 mm. in width distally. From the fourth they 

 gradually decrease in length and become less broad and dis- 

 appear completely on the 20th. The nine anterior caudal 

 vertebrae articulate with zygapophyses. Postzygapophyses are 

 lacking on the ninth, and the praezygapophyses become rudi- 

 mentary on the tenth but continue as rudiments on several 

 following vertebrae. The metapophyses are well developed on 

 the praezygapophyses of the 9 — 10 anterior caudal vertebrae 

 and may from there, together with the remains of the prae- 



Arlciv för zoolofji. B<1 3. S:o 3. 2 



