522 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 39. 



Alecto smithi d'Orbigny, Prodr. Pal., vol. 1, 1849, p. 317. 



Stomatopora smithi Gregory, Rep. Yorkshire Philos. Soc, 1894, p. 58, fig. 1; 



Ann. and Mag. Nat. Hist., ser. 6, vol. 15, 1895, p.226; Cat. Foss. Bryozoa, The 



Jurassic Bryozoa, 1896, p. 56, fig. 8. 



Gregory's description of this species follows: 



Zoarium hippothoiform, uniserial; branches crowded and irregular; entirely 

 adherent. 



Zooecia pyriform; long, slender, proximal ends; front wall well raised, rounded, 

 and punctate; orifice small, circular, surrounded by a low rim. 



Peristomes slightly raised. Flat, regular rims surround each of the zooecia. 



On account of the imperfection of Phillips's figures this species 

 was not understood until Gregory described and refigured the type- 

 specimen. As remarked by this author, the front walls of many 

 zooecia in this specimen are often broken away, giving it a schizo- 

 porellidan aspect. Gregory, however, fails to mention a most 



important matter, namely, the magnifica- 

 tion of his figure. Judging from other mag- 

 nifications in his volume, the figure, which 

 is herewith reproduced, is enlarged about 

 25 diameters, but until this point is accu- 

 rately determined the species can not be 

 considered as fully described. Stomatopora 

 smithi is undoubtedly a member of Cory- 

 notryjya, and, judging from its angle of di- 

 vergence (40°), is quite similar to the Ordo- 

 vician C. injiata (Hall). Gregory has given 

 its formula as p, c, l,r = l, 3, 2, 0, but from 

 the variation noted in other species, more 

 numerous specimens of C smithi would 

 show only the first and fourth terms to re- 

 main constant. 



Occurrence. — The type-specimen is incrusting Cardium citrinoidum 

 and was found in the Bathonian (Cornbrash) division of the Jurassic, 

 near Scarborough, England. 



CORYNOTRYPA DISSIMILIS SECTION. 



The four species assigned to this section form a less natural assem- 

 blage than those of the other two ^sections for the reason that they 

 are either intermediate, in some of their characters, between Coryno- 

 trypa and Stomatopora, or show relationship to the other sections of 

 Corynotrypa. The species selected as typical for the section has 

 well-marked characters which are shared by only one other species, 

 C. tennesseensis. These two forms constitute a small subsection char- 

 acterized (1) by a slight proximal constriction of the zocecium, giving 

 a small angle of divergence, and (2) by an aperture which, in addition 



Fig. 22. — Corynotrypa smithi. 

 Part of the type-specimen, in- 

 crusting A Cardium. Jurassic, 

 Bathonian, near Scarborough, 

 England. (After Gregory.) 



^M 



