170 BULLETIN 36. UNITED STATES NATIONAL MUSEUM. 



LAGENORHYNCHUS FITZROYI (Waterliouso). 

 (Plate 24, fig. 1.) 



Body anteriorly somewhat depressed, posteriorly compressed ; head 

 conical, arched above; the lower lip projecting beyond the upper; eye 

 placed above and behind, but near the angle of the mouth ; breathing- 

 vent situated in the same line as the eyes, supposing a circle to be taken 

 round the head. 



Upper parts of the body black, under parts j)ure white, the two blended 

 into each other by gray ; extremity of snout, a ring around the eye, the 

 edge of the under lip, and the tail-fiu black; dorsal and pectoral fins 

 dark gray ; a broad gray mark extends from the angle of the mouth to 

 the pectoral fin, above which tbe white runs through the eye and is 

 blended into gray over the eye; two broad deep gray bands are ex- 

 tended in an oblique manner along each side of the body, running from 

 the back downwards and backwards; iris of eye dark brown. 



Teeth |^*, slightly curved and conical. (Waterhouse.) 



Measurements of the exterior. — Total length (along curve of back), 5 

 feet 4 inches (IG2.G""); tip of muzzle to dorsal fin, 2 feet inches 5 

 lines (77.3'"'); length of mouth, 7 inches 9 lines (19.7""); height 

 of dorsal fin, G inches 4 lines (IG.l'"'); length of pectoral fin (along 

 anterior margin),! foot 2 1 inches (37.3'"'); breadth of fiukes, 1 foot 

 4 inches 5 lines (11.2' "'). 



Habitat.— St. Joseph's Bay, Patagonia, lat. 42° 30' S. 



LAGENORHYNCHUS CRUCIGER ((VOibiirny and Geivais). 

 (Plato, '25, figs. 1 and 2.) 



Beak short, only slightly marked off from the convexity of the fore- 

 head. 



Muzzle to the corner of the mouth, forehead, back, dorsal fin, tail 

 and pectoral fins black. On the sides, from the eye and base of the pec- 

 toral fins to the tail, a broad black band. This band is broadest above 

 the base of the pectoral fin, and decreases in width posteriorly until a 

 point about opposite the anus is reached, after which it again increases 

 in width and joins the black of the tail. Between the median and lat- 

 eral black bands and on the belly the color is white, more or less pure. 

 (D'Orbigny and Gervais.) 



Teeth .^^, skull smaller than that of L. </<?)(/?/.<?, but similar in propor- 

 tions. Rostral portion of i)remaxill;i' fiat, not twisted into a vertical 

 position at the distal extremity; their outer margins straight; triangu- 

 lar area high, flat, and smooth ; temporal fossa^ moderate, oval, directed 

 backwards; i^terygoid bones in contact in the median line, moderate, 

 very short antero posteriorly, not keeled laterally ; the conjoint postero- 

 internal free margin transverse, as in L. acutus ; vomer extending along 

 three-fourths of the rostrum, ai)pearing on the palate as a narrow ridge. 



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