ANATOMY OF MEGAPTERA LOXGIMAXA. 95 



are best marked on the 10th and 11th. They are shallow 

 cavities, in form the lower half of an ovoid, the point directed 

 inwards and downwards. The 10th measures 4 inches in the in- 

 ward and downward direction, 3 j inches antero-posteriorly ; the 

 greatest depth is^f inch. On the three first there is no pit, only 

 the blunt convex unfinished end of the processes. The thick blunt 

 end of the 3rd is more sloping below than above, but there is no 

 hollow or costal mark. The fossae begin on the 4th, where it 

 is well marked, increase in size and in depth backwards to the 

 10th, and diminish in size, but have sharper edges, on the 11th 

 and 12th. On the 13th there is a very shallow triangular facet, 

 2 inches wide. The 14th process presents only an elliptical 

 outer end, twice the thickness of the end of the 1st lumbar, 

 the lower and back part of which shows a slight costal bevel- 

 ling. 



The fossae reach to the outer end of the process and occupy 

 the posterior of the two nnder surfaces, as if formed by a 

 bifurcation of the inferior border of the process, but the an- 

 terior edge of the fossa is the prominent one. The surface 

 in front of the fossa, at first narrow, becomes gradually broader 

 as we go back, attaining on the 12th the same breadth as the 

 fossa. The fossse look mainly downwards, to a less extent out- 

 wards and backwards. Viewed from the side the ends of the 

 processes are seen to form crescents over the fossse, directed 

 very obliquely forwards and downwards, with a short con- 

 tinuation forwards from the 7th to the 12th. These margins 

 and the fossa? would probably be more sharply marked in the 

 completely ossified state. Here, taking the 7th, the thickness of 

 the unfinished edge, opposite the middle of the fossa, is 1 inch. 



21. Lumbo-Caudal Transverse Processes. — In pZace of 

 origin all the lumbo-caudal transverse processes, after the first, 

 are on a line with about the middle of the bodies. After the 2nd 

 lumbar they spring from rather nearer the front than the back 

 of the bodies ; in the caudal region it is rather the opposite, 

 this arising from the increased depth in the caudal region of 

 the anterior concavity of the neck of the process. 



In direction, the lumbar transverse processes have a more or 

 less forward tendency after the 1st, which is directed slightly 

 backwards (angle 5°). The 2nd is directed a little forwards, the 



