262 PROC. COTTESWOLD CLUB VOL. xill. (4) 



Date of Existence : — Truellii hemera, assuming that 

 Clvpeus-2^\\\ was contemporaneous with Truellii strata ot 

 Dorset. 



Remarks: — It hved considerably earher than the true 

 Terebratitla viaxillata, but it is a form with more old age 

 character. T. maxillata comes from a non-pHcate form of 

 the Terehr.-mariuorea ty[)e. Hie fact is that T. viaxillata, 

 T.perniaxillata, and T. snbiuaxillata are not truly genetic- 

 ally connected. They are heterochronous homoeomorphs, 

 independent plicate derivatives from a non plicate stock, 

 the plicate character being the old age feature which they 

 independently assume. 



18. PSEUDOGLOSSOTHYRIS sp. 



1899. TEREBRATULA GALEIFORMIS, var., Uptoii^ 



Cotteswold Brach. ; Proc. Cotteswold Club, 

 \'o!. XIII., pi. iii., figs. 1-4. 



I find some difficulty in agreeing with Mr Upton's 

 identification. The shell seems to be really an indepen- 

 dent development from Ps. simplex, whereof the in- 

 cipiently plicate form (PI. XII., figs. 1-3) indicates the 

 method of development. In that case it deserves a name 

 as a new species, separable at any rate from Ps.galeiforniis. 

 I hope Mr Upton will give it one. 



Notable Homceomorphs 



A notice of some of the more remarkable homoeo- 

 morphs is given below. They may be said to form 

 veritable " traps " in the matter of identification. Besides 

 them, there are the various uniplicate, and the various 

 bipHcate Terebratnla which are really homoeomorphous 

 developments ; so are what may be called the various quad- 

 riplicate forms of the T.-niaxillata series; so are the bilobate 

 ZeillericB ; and the different multiplicate series. 



