THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 177 



NAVEL AND MAMMARY SLITS. 



The navel in the Newfoundland Sulphurbottoms is a more or less elongated 

 scar, usually about 8 in. long, surrounded by the abdominal ridges and furrows, 

 which are somewhat displaced and bent outward by it and usually extend some- 

 what beyond it. (PL 17, figs. 1 and 2 ; pi. 18, figs. 3 and 4 ; pi. 19, fig. 2.) 



The mammae of the female are contained in longitudinal slits situated a little 

 above the median line and opposite the end of the clitoris. Above and below 

 these slits, or, in other words, nearer to and farther from the median line, are one or 

 several furrows which are parallel with the slits. The largest of these furrows is 

 commonly longer than the mammary slit and very deep. (See pi. 20, figs. 1 and 

 2.) In No. 8, 61 feet long, the mammaiy slits were 15 inches long. 



The mammary slits and other parts surrounding the sexual orifice do not cause 

 any marked convexity of the inferior outline of the body, but there is a slight de- 

 pression posteriorly which marks the position of the anus. (See pi. 19, fig. 3.) 



The male Sulphurbottom has rudimentary mammae of considerable size con- 

 cealed in slits like those of the female. (PL 20, figs. 3 and 4.) These slits are 

 situated about midway between the anus and penis orifice, and are unaccompanied 

 by parallel furrows. In No. 2 (length 71 feet), the left slit was 16 inches long 

 and the right 19 inches. The orifice of the sheath of the penis in No. 15 (length 

 63 ft. 6 in.) was 3 feet long. The penis itself in No. 2 (length 71 feet) was 6 

 feet long on the curve ; circumference of the glans at the base, 2 feet. Testicle 

 in No. 13 (length 65 ft. 11 in.), 27 inches long, 10 inches broad. 



FLUKES. 



The flukes were invariably cut off the Newfoundland Sulphurbottoms before 

 towing them in and I did not have an opportunity to see them in the adult. In a 

 foetus 12 feet long they had the form characteristic in the genus, convex anteriorly, 

 slightly concave posteriorly, with moderately recurved tips, and a central notch. 

 In No. 6, <? , 65 feet long, the depth of the flukes from the notch to the line of the 

 anterior base, or insertion, was 3 ft. 6 in.; in No. 11, , length 71 ft. 6 in., the 

 depth of the flukes at the same place was 3 ft. 8 in.; in No. 14, ?, length 77 ft. 

 2 in., the depth of flukes was 4 ft. 9 in. The depth of the notch in this individual 

 was 9 inches. It was very obtuse. 



WHALEBONE. 



The whalebone in the Newfoundland Sulphurbottoms (pi. 15, figs. 1 and 2; 

 pi. 16, figs. 3 and 4) is thick and black throughout, including the bristles, as in the 

 European specimens. In eleven specimens from the former locality, its length 

 above the gum (without the bristles) was as follows : 



