74 PROFESSOR STRUTHERS. 



of attachment look more outwards than in Megaptera. The trans- 

 verse processes here are directed so much forwards, that a ligament 

 passing from near the costo-transverse articulation to the costal 

 tubercle of the vertebra in front would be directed obliquely back- 

 wards.] 



Bodies of the Caudal Vertebra. 



8. H^MAL Tubercles, Ridges, and Groove. — The subverte- 

 bral ridge, single and sharp on the 10th lumbar,^ bifurcates on 

 the 1st caudal. Along the front half of the body of this, the first 

 caudal, vertebra there is a shallow groove, bounded by low 

 ridges about 1 inch apart ; then the nutritious foramina ; and 

 then, along the posterior third of the body, the haemal tubercles 

 rise rapidly, the space between them J inch deep and 1^ inch 

 wide. These tubercles are convex and blunt below, rather than 

 bevelled behind, for the support of the 1st chevron bone. From 

 the 2nd to the 6th the posteHor hcemal tubercles are larger 

 than those of the 1st, attaining their maximum on the 3rd. 

 They are bluntly triangular on side view. Their anterior border, 

 continuous wdth the edges of the haemal groove, is smooth. 

 Their posterior slope presents a flat triangular surface, about 

 2 inches broad at the summit, against which the anterior slope 

 of the chevron bone rests. Their summits are about 3 inches 

 apart, the triangular space between them 1 to 1| inch deep. 

 On the anterior half of these bodies (2nd to the 6th) the hsemal 

 groove is bounded by sharp edges. 



The a/iiterior lucmal tubercle, smaller than the posterior, 

 increases gradually from the 2nd to the 6th; diminishing gradu- 

 ally the interval between the anterior and posterior tubercles. 

 This interval becomes a mere notch on the 6th by the curving 

 forwards of the posterior tubercle. This notch, half-oval in 

 shape and about two fingers'-breadth, is converted on the 7th 

 vertebra into a foramen by the meeting of the posterior and 

 anterior tubercles. The now-constituted hernial ridge is per- 

 forated laterally on the 8th as well as on the 7th, forming the 

 first stage of the vertical passage in these two vertebrae. On 



^ Rmlolphi, loc. ciL, speaks of and figures eleven lumbar vertebra ; Van Beueden 

 and Gervais, loc. cit., speak of " neuf lombaires et vingt-deux caudales," but 

 figure the lumbar as ten (pis. x. and xi. ). It is evident tliat the vertebra which 

 I assign as the 1st caudal is really so, and therefore that ten is the correct 

 number of the lumbar vertebra;. 



