271 
TWO NEW LOWER SILURIAN SPECIES OF LICHAS 
(SUBGENUS HOPLOLICHAS). 
By E. O. Ulrich, Newport, Ky. 
Lichas (Hoplolichas) robbinsi, n. sp. 
Fig. 1. (I, imperfect glabella of the natural size; b. profile of same. 
Specimen wanting the free cheeks and defective at the inner edge and 
at the center of the occipital ring. 
Glabella, including frontal prolongation, with the length equal- 
ling one and one-half times the greatest width. Without the 
frontal process the width is greater than the length. Frontal 
lobe very gently convex and with parallel margins in the posterior 
half, then expanding, the anterior half grows tumid and finally is 
produced forward into a single strong baculate process. Lateral 
lobes undivided, with margins almost parallel, the width and length 
about as one is to two and one-half, ver}' little convex except in 
front where they bend outward and downward to the frontal mar- 
gin. Furrows between the central and lateral lobes very narrow; 
likewise the occipital furrow. Occipital ring rather narrow at the 
ends, nearly twice as wide in the middle where it probabl}' sup- 
ported one or two central spines. Facial sutures apparently 
normal. Fixed cheeks of the form shown in the drawings, slightly 
depressed and with a linear curved impression immediately liehind 
the eyes. Surface covered with papillae just visible to the naked 
eye. At intervals of one or two mm. there is a larger one. Free 
cheeks, ej-es and thorax not observed. 
Since these two species, excepting the doubtful L. Jn/hins Hall, 
are the first to be described from American rocks having the 
characters of the subgenus /fo^>7o/<V/*f^s, Dames, they are not likely 
