INTESTINAL TBACT OF RIKDS. 



237 



larger. However, the most striking circumstance is the appearance above the ca;ca in 

 the posterior part of Meckel's tract of a set of kinks drained by the rectal vein. In the 

 drawing, the relative importance of these has lieeii slightly exaggerated ; but I was 

 anxious to call attention to them, as their presence suggests either an unlikely ailinity 

 between the Larida^ (and the Alcidae) and the Pelargo-Colyml)oraorphine assemblage, or, 

 more probably, that the existence of tiiis kink is a miiltiradial apocentricity to which too 

 much importance must not be attached. In Slercorarlm crepidatns (tig. 5o, p. 2:55) a 



Fi-. .17. 



rnte>tinal Tract of Frnlercula arclicii. Lettering as in tij;. -11. 



more archecentric type of gut is displayed, the arrangement rather closely resembling 

 that found in Thinocor^is and Glareola. The duodenum is simple. Meckel's tract exhibits 

 two loops proximad of tlie diverticulum, while distad of it is a vei-y Avide area re])re- 

 senting a supra-duodeual fold and an undifferentiated loo]) " c." The cteca are long aiul 

 the rectum is straight. In Sfcrna hlrundo (fig. 50) the conformation is more apocenlric, 

 and the pattern reseml)les that Ju many of the specialized (Iruiform and Charadriiform 

 types. Meckel's tract is thrown into three minor loops, which, however, are better left 



SECOND SERIES. — ZOOLOGY, VOL. VIII. 3C 



