Habrostroma is known from the Upper Silurian through the Middle Devonian. It is the most prominent stromatoporoid genus in the North American lower Lower Devonian (Lochkovian). In the past we used multivariate statistics on 106 specimens from the Manlius and Coeymans Formations of New York, and determined that two species of Habrostroma are present: H. consimile (Girty); and H. centrotum (Girty). Now we extend our methodology to include five published specimens from the Keyser Formation (Jersey Shore Member and overlying Lavale member) of western Virginia, and two published specimens from the Stuart Bay Formation of Bathurst Island, Arctic Canada. In addition, we include six previously unpublished specimens from the Beck Pond Limestone of western Maine.

Preliminary results of cluster analysis show that nearly all New York specimens retain their identity as Habrostroma consimile or H. centrotum. Two specimens from the Lavale Member of the Keyser Formation and one of the older specimens from Maine cluster with H. consimile. A third cluster contains the three specimens from the Jersey Shore Member of the Keyser. A fourth cluster contains one Bathurst Island specimen and three of the younger Maine specimens, and a fifth cluster contains the other Canadian specimen plus one younger and one older Maine specimen. The last three clusters probably represent new species.