60 ANATOMY OF VERTEERATES. 



recalling the surface of the skull m the Crocodiles. The occiput 

 is concave, and separated by a strongly developed ridge from the 

 temporal fossie, which almost meet at the vertex. The bony 

 septum of the orbits is complete, and formed by two strong plates, 

 separated by an intermediate cellular diploe, except at the pos- 

 terior part. The optic foramina are distinct ; each is directed 

 transversely outwards. 



In the Woodpeckers the cranium is rounded, the temporal 

 fossa3 shallow, the internal wall or septum of the orbits incom- 

 plete, but the anterior boundary is well developed. The posterior 

 facet of the cranium is raised. The superior surface is traversed 

 by a wide furroAv extending longitudinally forward, generally to 

 the right, but sometimes also to the left, as far as the lacrymal bone. 

 In some of the larger species of Woodpecker, as the Picus major, 

 L., the cranial furrow is more symmetrical. In the Humming- 

 birds it is double, the hyoidean furrows being separated at first 

 by the cerebellic protuberance, and afterwards by a mesial longi- 

 tudinal ridge. 



The skull is remarkable for its length in the majority of the 

 Waders. In the Herons and Bitterns the occipital region is low, 

 and inclines from below upward and forward; it is separated 

 from the upper and lateral regions by a well-developed, sharp, 

 lambdoidal crest ; and it is divided into two lateral moieties by a 

 slight longitudinal ridge. The temporal fossae are deep and wide, 

 and extend upward to the sagittal line, along Avhich an osseous 

 crest is developed. The cranium is expanded anteriorly to the 

 above fossae, for the lodgment of the cerebral hemispheres, the 

 interspace of which is indicated by a deep longitudinal furrow. 

 The roof of the orbits is expanded laterally, which gives great 

 breadth to this part of the head, but the posterior orbital walls 

 are very imperfect, and the internal Avails or septum almost wholly 

 Avanting. The optic foramina are blended with each other and 

 with the smaller foramina, which in other birds represent the fora- 

 men lacerum orhitale. 



Woodcocks, Snipes, Curlews, and LapAA^ngs resemble Herons 

 in their defective bony orbits ; but they AA-ant the extended 

 superior parietes of those cavities, and differ much in the almost 

 spherical form of the cranium, AAdiich is smooth and devoid of the 

 muscular ridges characteristic of the fish-feeding Grallce. In 

 this order the premaxillary bones present some of their most 

 eccentric forms. They are narroAv, elongated, and curA^ed doAAai- 

 Avard in the Ibises and CurlcAvs; bent upAvard in the contrary 



