13 



or pituitary (pace in front of the ban-occipital cartilage remains permanently open, but ha 

 been converted into the posterior aperture of the naao-palatinr ranal. The iphenoidal arc he* 

 are very abort, approximated toward* the middle line ; and the presphenoid and vomerine 

 cartilage is brought back, cloier to the ipheuoidal arches. Two cartilaginous arches circum- 

 scribe elliptical spaces, outside the presphenoid plate : these appear to represent the ptery- 

 goid arches ; but, as in the embryo of higher fishes, are not separated from the base of the 

 skull by distinct joints. The basal cartilages, after forming the ear-capsules, extend upward* 

 upon the sides of the cranium, arch over its back part, and leave only its upper and middle 

 part membranous, as in the human embryo when ossification of the cranium commence*.. 

 Two broad cartilages represent, upon the roof of the infundibular suctorial mouth, the pala- 

 tine and maxillary bones, and anterior to these there is a labial cartilage ; there are likewiiw 

 cartilaginous processes for the support of the large dentigerous tongue, and the attachment 

 of its muscles. 



The structure and grade of development of the spinal column accord with those described 

 in Preparation No. 9. The processes, answering to the 'epibranchials* in osseous fishes, come 

 off from a cartilaginous tract on each side of the notochord, and after a short course out- 

 wards and downwards, divide, each, into three branches, one passing forwards, one backwards, 

 and the intermediate branch, answering to the ' ceratobranchial,' downwards : this, after send- 

 ing off processes which surround the branchial apertures, descends, bends inwards, dilates, 

 and is perforated ; then contracts and joins a long and broad ' hypobranchial ' cartilage. The 

 posterior pair of ceratobranchials constitute, with the hypobranchial, a |>erforated cartilagi- 

 nous case, which is lined by the pericardium, and contains and protects the heart. 



Prepared by Mr. George Hambrow, Anatomical Student. 



35. The dried conical lip, with the labial cartilages and teeth of a Lamprey (Petro- 

 tHjrzo* mariiuu). Purcka*ed. 



In all the skeletons and skulls in which the individual bones are numbered, the 

 numbers answer to those in the first column of TABLE I. of SYNONYMS, and the 

 names under which such bones are noticed or described are those given in the second 

 column of the same TABLE, under the head CATALOGUE. The synonyms are chosen 

 from the Works of the two great French Anatomists, CCVIER and GEOFFROY- 

 ST. HILAIRE, who have most advanced Osteological science; from Dr. HALLMANN'* 

 elaborate 'Treatise on the Temporal Bone;' and from two comprehensive German 

 Works on Comparative Anatomy, viz. those of MKCK.EL and WAGNER. The syno- 

 nyms of the bones of the head of Pishes are taken from the celebrated Work on 

 Fossil Fishes by the distinguished Ichthyologist of Ncuchatel ; and the Anthropoto- 

 mical terms have been chosen from SOEMMERRING'S classical Work, ' De Corporis 

 1 1 ii i nan i Fubrica.' 



