A treatise on zoology . r below the Jurassic, and thus offer tothe systematist at once the best opportunity for tracing outphylogeny, and a most confusing number of intermediate the most recent advances in the classification we are chieflyindebted to Gill [165], Giinther [191-92], Sagemehl [379], Jordan[250-51], A. 8. AVoodward [505], and Boulenger [40-42]. In the skull we notice a general tendency, already referred to(p. 222), for the dermal bones to sink deep lielow the surface,leaving lateral-line ossicles in the skin (Allis [16, 19]), Parker [319],Schleip [387], Gaupp [151(7]. Th
A treatise on zoology . r below the Jurassic, and thus offer tothe systematist at once the best opportunity for tracing outphylogeny, and a most confusing number of intermediate the most recent advances in the classification we are chieflyindebted to Gill [165], Giinther [191-92], Sagemehl [379], Jordan[250-51], A. 8. AVoodward [505], and Boulenger [40-42]. In the skull we notice a general tendency, already referred to(p. 222), for the dermal bones to sink deep lielow the surface,leaving lateral-line ossicles in the skin (Allis [16, 19]), Parker [319],Schleip [387], Gaupp [151(7]. The prefrontal (ectethmoid, 346 TELEOSTEI parethmoid) and post-frontal- (sphenotic), and even the pterotic( squamosal), may thus become converted into entirely cartilagebones. The parietal region often becomes grown over l>y thetrunk myotomes from behind (as in the Gadidae, Fig. 328), andthe supraoccipital then develops a vertical crest. The musclesmay simply cover the parietals or they may project into a post- -Ih pmx. pcp--- Pio. view of the skull of Cpprinus carpio, L. A dotted line indicates the lateral-linecanals on the left .side, epo, epiotic ; eth, pre-ethmoid (rostral); /;•, frontal; I, lachrymal ;meth, mesethmoid ; mr, maxilla ; op, opercular; pa, parietal; pal, palatine ; pf, prefrontal;pmx, preinaxilla; pop, preopercular; ptf, postfrontal ; pto, pterotic ; so6, supraorbital ;.soc, supraoccipital ; .-;///, suprateniporal ; st, anterior suprateuiporal. temporal foramen, as in Amia, tending to separate the parietals fromthe cranial wall. This post-temporal fossa is often present in thelower families (Elopidae, Albulidae, Osteoglossidae, Clupeidae, etc.).It may be roofed over by the epiotic and pterotic as well as theparietal. A suprateniporal (extrascapular) is often present, but islost in the higher sub-orders (Figs. 329-31). The position of the parietals is important. It may safely SKULL 347 be assumed that the condition in which tlie parietals meet i
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectzoology
