658 



THE AMERICAN NATURALIST 



[Vol. XLI 



Bothriolepis presumably lived in fresh or l)iii( kisli w-.wcv, and moved 

 in large schools. One of the slabs slxmcd some icu individuals 

 headed in the same direction. Ferns and ])]ant stems turned in the 

 opposite direction showed that they Avere moving against the current. 

 Another slab contained four specimens moving in the same direction 

 but lying at different levels, indicating that two at least were buried 

 in the sand when killed. Tlie inlenial structure of Bothriolepis, in- 

 cluding its stomach and tin- arraiiorment of its gills, was shown in 

 serial sections of the fossils. In sindving the ancestry of vertebrates 

 Professor Patten desired furilier kuou ledge of Bothriolepis than could 

 be supplied from any existing collcciioii, and llien^fore he collected for 

 himself the group of fossils exhil)it( il. Mis thcorv ol vcrteWrate devel- 

 opment from arthropod prototypes was illnstralc<| hy son)e fifty clay 

 models. They were designed "to ^Unw how tiif rarlier vertebrate 

 stages are but a further specialization of the later stages of an arach- 

 nid. The models show the origin of th(^ l)lastopore, the unfolding of 

 the cranial sense organs, the relation of the cranial neuromeres to the 

 cephalothorax, the origin of concrescence, the derivation of the o])er- 

 culum and branchial chambers, the lateral fold, visceral arches, and 

 the union of the anterior visceral arches on the haemal side to form 

 the premaxillae, maxillae, and mandibles." One series of models 

 illustrated the relation between ecliinodenn larvae and arthropod half- 



Dr. C. R. pLtman of Harvard I'niversiiv sliow(>(l specimens of 

 the head shields of lung fishes, so that the ^^ell knou n Seolii.h I)e^o- 

 nian form could be com[)ared with the less known Canadian >eaumen- 

 acia, and also whh existinir lim<r fislies. 



Mr. C. H. S. Sternlnr- of I ..u.en.e. K..n^„^. v ho ha> <-ollected 



"Red rhalk"'of Kaii^a.. to-dher uith a .pe. im.-n ot Ih^)H,nmis 

 rcgalh. The latter <lo. . not in. hide the skulk l.ui the cervical verte- 

 brae ANcre found, and .hou that ih.- bird had l..n-er ne< k th,.n ...me 



pe]^i. i. Mell preMM-N..I Tl,e dl^.■r ..Mil position ol tin- I.-n i. similar 



!i plpniarai'.'mn't ot' lii'.' experi.'-n-v. a'^ a .•..ll.'. i.n'. .-ntille.! "The Life 

 of a Fos.il Hunter." toi ^^ hi( h i>iofew.r II. 1". ( Kl.orn lia. written an 

 introduction. 



