526 



rR0CEEDING8 OF THE NATIOlSfAL MUSEUM. 



VOL. 39. 



tively large, averaging 1 mm. in length, irregularl}- club-shaped, the 

 anterior half swollen, with a maximum diameter of 0.40 mm., tapering 

 gradually in the posterior half to the narrowest part with a width of 

 0.15 mm., where it joins the distal end of the preceding one. Aper- 

 tures subterminal, surrounded bj' a slight border, and with a diameter 

 slisfhtlv more than one-third that of the zooecium. 



This species, which is named in honor of Prof. Charles Schuchert, 

 who collected the type-specimen, is related most closely to the 

 common American form C. inflata, but differs conspicuously, how- 

 ever, in having larger, less regular, more elongate and less rapidly 

 tapering zooecia. From other members of the C. dissimilis group it 

 is distinguished by its constricted aperture. 



Occurrence. — Rare in the Wesenberg limestone at Wesenberg, 

 Esthonia, Russia. 



Holotype.— Cat. no. 57111, U.S.N.M. 



CORYNOTRYPA CANADENSIS (Whiteaves). 



Stomatopora canadensis Whiteaves, Pal. Foss., vol. 3, 1897, p. 161, pi. 18, figs. 



4, 4«. 



Through the courtesy of the Dnector of the Geological Survey of 

 Canada, I am able to refigure the type of this species, which was well 



described by Professor Whiteaves, al- 

 though his illustrations are inadequate 

 for careful discrimination. Comparhig 

 figure 27 with figures 23 to 26, the 

 close relationship of these four species 

 can not fail to be apparent. With one 

 exception, C. tennesseensis, the zooecia 

 are of equal size. The specific distinc- 

 tions must, therefore, be based on 

 differences in the aperture, surface 

 ornamentation, and angle of diver- 

 gence. C. sclmcherti has the most 

 constricted aperture and in this respect 

 is more closely related to the C injiata 

 section than to the present group of 

 species. This relationship is further 

 indicated by the constricted proximal 

 portion of the zooecium. C. cana- 

 densis, although of exactly the same 

 size, is less constricted in the proximal 

 area and also has a wider aperture, 

 which, in addition, is slightly exsert. Wliile C. scJiucherti may be 

 considered as intermediate between C. canadensis and C. injiata, 

 C. canadensis likewise represents a stage between C. schucJierti and G. 



Fig. 27.— Corynotrtpa canadexsis. 

 o, portion of ttpe-specimex, x9; 6, 

 front and side views of a zocecium , 

 X9. Middle Ordovician, Swampy 

 Island, Lake Winnipeg, Canada. 



i 



