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ANNALS NEW YORK ACADEMY OF SCIENCES 



As a matter of special interest, but also of insufficient evidence, the 

 strange arrangement of several specimens around a common center 

 demands careful attention. It was originally figured by Salter and 

 Goeppert. Afterward, however, it was questioned by the majority of 

 authors, but was recently again mentioned by Fearnsides ((3), p. 307) 

 and I likewise have observed some examples, particularly of early stages 

 which can be classed herewith. Fig. la on plate XXI presents two 

 Dictyonemas opposite each other, each of them attached to a minute 

 common disk. Fig. 2c shows two young individuals joined to each other 

 by means of their proximal parts. I observed also four full-grown speci- 

 mens of the variety acadica m. f. ruedemanni, uniting as appears in the 

 text-figure 2. In all the examples studied, no nema and only once a 



common disk is present, so that an imme- 

 diate fixation by the basal parts of the colo- 

 nies must be assumed. If this is the fact, 

 which I am rather inclined to hold on ac- 

 count of the specimen discussed, a colonial 

 arrangement of the third order possibly ex- 

 isted comparable with that. of Diplograptus 

 pristis. 



The statements thus far made about the 

 association of the faunula with Dictyonema 

 fig. 2.— Dictyonema flaoeiuforme flabelliforme do not vary to any consider- 



var. acadica m. f. ruedemanni a bl e extent, provided that we will except 



the fossils gathered from interbedded limy 

 nodules ("orstensbollarne"). G. F- Matthew 25 pointed out that in the 

 Dictyonema-shales of New Brunswick, two bands (b, c) are distinguish- 

 able, namely, a lower one with var. conferta as the predominant type 

 besides var. acadica and a higher one containing . an abundance of the 

 var. acadica and also var. norwegica. At Navy Island, both zones fur- 

 nish the "Bryograpti" and a few brachiopods, the latter being better 

 represented on the section of McLeod brook. In the slate belt of East- 

 ern New York, Buedemann, 26 though not able to fix the relative position, 

 again recognized the Dictyonema bed separated from the Staurograptus 

 bed, which also contains Dictyonema flabelliforme var. acadica, together 

 with several species of brachiopods, identical with those of Matthew. 

 As to the European occurrence, the best recent explorations were made 

 by Moberg (2) and Westergard (4), who generally agree with each other 



23 See references (10), (11), (12) and "On a New Horizon in the St. John Group," 

 Can. Rec. Science, Vol. 4, No. 7, p. 339. 1891. 

 23 Cf. footnote No. 15. 



