22 



61. The right moiety of the skull of a Carp (Cyprinus Carpio). The numbers upon 



the bones indicate their names according to Table I. 



In this specimen may be noticed the position and size of the parietal bone ; it meets its 

 fellow at a sagittal suture on the upper surface of the head, which is a rare structure in the 

 class of Fishes, although the normal one in the Vertebrate Series. Here also may be seen the 

 superorbital scale-bone, and the perforated hypapophysis of the basioccipital, which supports 

 the peculiar large brown-coloured dental plate. The opercular bones present a remarkably 

 dense osseous texture. The ordinary bones of the mouth are all edentulous. 



Presented by Prof. Owen. 



62. The two inferior pharyngeal bones and the upper pharyngeal tooth, with the 



portion of the basioccipital bone to which it is attached, of a Carp (Cyprinus 

 Carpio), said to have been fifty years old. The teeth are of the molar type, 

 and present a complicated triturating surface : they are attached to the inner 

 side of the pharyngeal bones by a confluence of their base with the osseous sub- 

 stance. The bones supporting them are modified hypobranchial elements of 

 the fifth pair of arches : they are smaller, stronger, and more curved than 

 the true branchial arches which are anterior to them. Purchased. 



63. The separated and artificially articulated bones of the head of a Carp (Cyprinus 



Carpio), in which the bones are indicated by numbers according to Table I., 

 and the natural segments of the skull by the colours of the labels according 

 to Table II. Yellow denotes the occipital segment or vertebra; green the 

 parietal one ; blue the frontal, and red the nasal segments. 



The following peculiarities may be noticed in this specimen. The under part of the basi- 

 occipital (i) either developes a large hypapophysis, or by the confluence therewith of a 

 pharyngobranchial bone, is converted into a longitudinally perforated process, the under part 

 of which expands into a broad triangular plate, and supports the upper pharyngeal grinding 

 tooth. The exoccipitals (n, i) are perforated by unusually large foramina. The superoccipital 

 (3) is triangular ; but its base is formed by the superior border which articulates with the 

 parietal bones. The alisphenoid (a) is perforated at its centre by the facial nerve, or oper- 

 cular branch of the trigeminal : a more posterior foramen gives exit to the glossopharyngeal : 

 the third division of the fifth escapes from a foramen common to the alisphenoid and orbito- 

 sphenoid (10). The orbitosphenoids are large, as in most Malacopteri. The entosphenoid (') 

 is unusually large in the Carp. The premaxillary (s) and premandibular (32) are small and 

 edentulous. There is a small prenasal bone (is') ; and a superorbital (ri) as well as subor- 

 bital bones (71). 



Purchased. 



