454 SYSTEMATIC PALEONTOLOGY 



Genus DICTYOCORYNE Ehrenberg. 

 DiCTYOCORYNE PROFUNDA Ehrenberg. 



Plate CXXX, Figs. 11, 12, 13. 



Dictyocorifne profunda Ehreubcro:, 1860, Monatsbericbte d. k. Akud. d. Wiss. Berlin, 

 p. 767. (Name only.) 



Dictyocoryne profunda Ebienberg, 1872, Monatsbericbte d. k. Akad. d. Wiss. Ber- 

 lin, p. 307. 



Dictyocoryne profiuidn Ebrenberg, 1872, Abbaiid. d. k. Akad. d. Wiss. Berlin, pi. 

 vii, lig. 23. 



Dictyocoryne profunda Ilaeekel, 1887, Cbal. Kept., vol. xviii, jit. i, p. 592. 



Description. — '' Forma obtuse triangularis triactis, radiis clavatis 

 subasqualiter sine ordine cellulosis, connecticulo membranaceo laxius 

 celluloso, cellulis sa?pe subquadratis. Long. Max. j^j'", radii a medio yV". 

 Cellulffi in capitulo transversae fere 15." Ehrenberg, 1873. 



Arms approximately of equal size and equidistant, club-shaped, from 

 2^ to 3 times as broad at the ends as in the narrowest part, broadest part 

 twice the diameter of the central disk, length 2^ to 3 times the diameter 

 of the central disk; central disk with three or four concentric rings; 

 patagium reaching almost or quite to the ends of the arms. 



The forms here referred to this species show considerable variation 

 within themselves, and if they all remain here will make it necessary to 

 broaden the descriptions given by Ehrenberg and by Haeckel. With the 

 material now at hand it seems better to broaden the species than to 

 describe new ones. The three figures show the range of variation observed 

 in the Maryland forms. 



It may be seen from the figures that the arms are not absolutely equi- 

 distant as they are supposed to always be in this genus. The maximum 

 variation in this respect is shown in Fig. 11 where the angles between 

 the arms are 105°, 123° and 133°. This does not invalidate the refer- 

 ence of this form to Dictyocoryne for Ehrenberg's figure of the type of 

 the genus show-s the arms as being at angles of 113°, 133° and 134°. 



Occurrence. — Calvert Formation. Lyons Creek, Popes Creek, Plum 

 Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Rev. Edv/ard Huber. 



