A Note on the Genera Staurocephalus and Sphaerocoryphe, with the Description of a New Species of Sphaerocoryphe

Abstract

There has been some confusion between the trilobite genera Staurocephalus and Sphaerocoryphe. This is probably due to a similarity in the bulbous character of the anterior glabellar lobe common to both genera as well as to the genus Deiphon and the Australian form Onycopyge. King (1920, pp. 532–4), in view of the character of a hypostome of Staurocephalus preserved in the British Museum and figured by Salter, was of opinion that this genus should be removed from the Cheiruridae, but hesitated to place it in the Encrinuridae. Raymond, in Eastman's Zittel (1913, p. 725), includes Staurocephalus and Sphaerocoryphe in his subfamily Deiphoninae, which he defines as Cheiruridae with a bulbous anterior lobe. His diagnosis of Staurocephalus is “Glabella with two pairs of lobes behind the bulbous portion. Cephalon with a denticulate border, and pygidium similar to that of Pliomera”. Sphaerocoryphe has only one pair of lobes behind the bulbous anterior lobe. It is necessary to consider the characteristic features of the genotypes of the two genera.