71 



atlaa, but the chief put of the articulation U formed by thr two oblong surfaces presented 

 by the cxoccipitals. The** dement* meet abort the foremen magnum, where they form |>n 

 of tin- II|I|MT surface of the head. The parocripital* present thr usual concavr surface for 

 the suprascapula. The luperoccipital forms a horizontal (lightly convex plate furrounilrtl 

 by the exoccipitals, paroccipttals, mastoid* and parietal*. The mastoids harr a great trmi- 

 verae extent. The frontal* are of unusual die, are joined together by the frontal nature, aiul 

 form the middle part of the upper surface of the cranium. The naial bones are of consider- 

 able breadth, and are united by a thin layer of bone at the middle lino. A membranous 

 fontanellc has existed between them and the frontal*. The orbit is completed below by a 

 chain of suborbital bone*. The tympanic pedicle articulate* by the epitympanic with the 

 mastoid, and, apparently, by the pretympanic with the postfrontal. The hyoid arch supports 

 ten branchiostcgal ray* on each side. The ooracoid* are bent upon themselves so a* to form 

 a deep channel on their convex side. The pubic bone*, which are attached to the inner side 

 of the coracoids, send backwards a small process from their symphysial uiu'ou. The neural 

 spine* begin to rise at the sixth and seventh vertebnc, beneath the posterior extremity of the 

 suctorial disk. The osseous basis of this disk is formed by the intcnieural spines, which 

 expand into transverse bar* at their mmmits and receive at their inters|iares the transversely 

 developed dermal spines which overlap each other, and support each a finely denticulated 

 transverse ridge along the middle of their upper surface : these ridges incline backwards, and 

 are flexible. The bodies of the vertebrae are smooth, elongated, and much compressed in 

 the middle. The parapophyses are moderately long, and extend horizontally outwards and 

 a little forwards : the cpipleural spines begin to be developed from those of the alia-, and the 

 pleurapophyte* from those of the third vertebra. The first pleurapophysis U short, increases 

 in breadth a* it descends, and bifurcates at it* lower extremity : the rest of the plrurapn- 

 phy*e are simple, and progressively decrease in length from the fifth to the tenth : those of 

 the eleventh pair bend inwards and meet below, but the haemal arch of the succeeding verte- 

 bra is formed by a similar disposition of the parapophyses. The epipleural spines continue 

 to be developed from the first five caudal vertebra : in the eight anterior abdominal vertebrar 

 they extend outwards and backwards, and form, with the elongated parapophyses, the basis 

 of rapport to the suctorial disk. 



Presented by George Bmnetf, Esq., F.L.S. 



The skull, with the integuments and sucking disk, of a large Remora. The 

 two large exoccipital comlyles and intermediate basioccipital concavity art- 

 well shown, a* also the characteristic extension of the teeth u]>on the exterior 

 surface of the jaws. Presented by George Bennett, tg., F.L.S. 



299. The branchial arches of the Sucking-fish (Eckenei* Remora). 



The first pair sends off from its anterior border a scries of pointed processes and from it* 

 posterior margin a series of tubercles ; corresponding tubercle* are developed from the side* 

 of the second, third and fourth arches. They interlock with each other like the teeth of a 

 cogwheel, and prevent the entry of food or other foreign irritating matters into the intcnrpare* 



