-\ o. 4<)()] ORrilOGKNETIC ] 'A HI A TION 



625 



A similar position with reference to my work is taken by Coss- 



Referring again to the Red Sea shells cited by Sturany, and used 

 by Boettger and by Giard as illustrations of heterostylism in 

 Gastropods due to diverse physical conditions, we note on reference 

 to Sturany's illustrations that the difference between the proto- 

 conchs of F. hifrons, and F. 'pmicicosta is one of degree and not of 

 kind. Both protoconchs are of the same type, the true Fusiis 

 type; but that of F. paiicicosta has a somewhat larger iuuial whorl. 

 This species is a highly accelerated ty])e, as compared with 

 hijrons, and hence it is not surjmsiiig to find tlio ])r()tocoiic]i par- 

 taking of this acceleration. Besides the initial larger whorl, the 

 number of whorls appears to be less than in /''. hil'ron.s where \\ 

 smooth volutions, followed by a (lehcarely ribbt^d portion constitute 



toconchs of FiiMis will show manv Mi.-h \iin;Uion>. (see pi. xvii, 

 figs 1-4) all of ^\hi( h .uc m. le iii.Hhh( .iMon> «hir to ui< .iter or le^^ 



pwtiHniuh Ni(h a <hlhnn.c ot t p.- (I.x ^ hou ( \ . i (xi^tb. tueen 

 the pioto-oMch. ot F,i.n> .in.l 1 ..Uifu^ii. .md rnlo„,nfu.u. and 



^\ill no doubt (oiiMiH, aiixoiH \Mu u m 1 umi. ot ih( IImI -ca. 

 the.lM|.Ma toMii ha. a lau i .mtial and l.u.i Mil.M.piuu ulioiU 



with the littoral tyj)c. In ab>cn(v ol" hu-urcs and detailed 

 description such as one Iia^ a nuht to ('X[)im1 m a work of tlu> kind 

 prcMiitMl U -tu'an it nn,)o..,blr to i-idur in uhat th.. .htlVi- 

 eiucualh .onHM. AIom,,ui on. i. Id to <lohbt tlu a^nuKy 



ulun tht Mat ni.nt. 'It ao.n L tioni tln^' tabnlation. thatdiJ 



dc la Iklqiqur. UtO.-,. T. X\.V1\. p. Kid. 



