A new type of graptolite synrhabdosome

Three remarkable graptolite synrhabdosomes frorn the Lower Llandoverian shales (revolutus Zone) on Bornholm are described and discussed. 1\vo of the synrhabdosomes are composed of rhabdosomes of Rhaphidograptus toernquisti (Elles & Wood), the third includes climacograptid rhabdosomes that are not assigned to species. The synrhabdosomes are remarkable in that the stipes are attached by the;, yirgellae. This is the reverse of the situation in previously known synrhabdosomes in which attachment is by the vir­gulae. The mode of formation of the synrhabdosomes is discussed, but for the present there remain many unexplained details of the development.