October, 1913. New Trilobites — Slocom 69 



Locality and horizon. — The type (Mus. No. P 16755) was col- 

 lected by the writer in July, 19 10, in the Lower Maquoketa shale 

 at Clermont, Iowa. Other specimens were collected by the writer 

 from the Lower Maquoketa beds at Clermont, Elgin, and Bloomfield, 

 Iowa. 



Calymene gracilis sp. nov. Plate XVIII, Fig. 9. 



Type specimen No. P 17065 Field Museum. 



Body small, in form and general proportions similar to other species 

 of the genus. The surface of the test appears smooth to the naked eye 

 but under a magnifier it appears very finely papillose. 



Cephalon sublunate, width of the genal angles somewhat less than 

 twice the length on the median line, about as 7 : 4. Anterior border 

 flat, projecting obliquely fonvard and upward, not recurved; separated 

 from the glabella by a deep, narrow, marginal furrow. The dorsal fur- 

 rows, in passing forward from the occipital ring, diverge slightly near the 

 posterior glabella lobes, then converge until they meet the anterior 

 marginal furrow. Here the dorsal furrows become nearly obsolete on 

 account of a large rounded node on each fixed cheek, opposite the 

 anterior lobe of the glabella. Glabella convex, elevated above the 

 cheeks, shorter than is usual in this genus, widest at the posterior lobes 

 where the width is equal to the length, including the occipital ring, much 

 narrower anteriorly; anterior lobe transverse, width less than one-third 

 the length; first lateral lobes well defined, about the width of the ante- 

 rior lobe and terminating about the same distance from the median line ; 

 second lateral lobes larger and node-like; posterior lateral lobes much 

 larger, forming a pair of conspicuous nodes at the base of the glabella. 

 Lateral furrows well defined but not crossing the glabella. The first 

 pair transverse; second pair somewhat larger, but bent slightly back- 

 ward; posterior pair broader and deeper, curved backward towards, but 

 not reaching, the occipital furrow; at about two-thirds of their length 

 from the dorsal furrows they bifurcate; the shorter fork extends toward 

 the median line of the glabella, forming a well-defined node between the 

 second and posterior lobes. The facial sutures originate just in front of 

 the genal angles, curve forward and inward over the palpebral lobes 

 and thence forward to the anterior margin. Occipital ring prominent, 

 slightly wider in the middle, separated from the rest of the glabella by a 

 well-defined occipital furrow. Cheeks only moderately convex aside 

 from the palpebral lobes, which are long for this genus and rise very 

 abruptly from the dorsal furrows; lateral marginal borders wide and 

 well rounded, posterior border much narrower; all are defined by deep 

 marginal furrows. 



