Calymene Diops.[19] Green. Cast No. 8, and fig. 2.
[19] From the Greek for "Double Eyes."
Clypeo lobato plano; rugis tribus in lateribus frontis; tuberculis oculiformibus, eminentissimis et duplicibus; articulis octodecim; cauda rotunda.
This species is very distinct from every other Calymene that we have seen. The outline of the buckler is lobate lunate; the front is very convex, and a good deal elevated above the cheeks or sides, from which it is divided by a deep furrow; on the posterior margin of the front on each side, close to the groove there is a prominent circular tubercle, before which there are three small transverse wrinkles. The cheeks are subtriangular; the oculiform tubercle is near the posterior superior angle, and is only separated from the tubercle on the front, by the furrow or groove, so that the animal seems to have had double eyes on each side; there are two curved lines on each side below the eyes, crossed near the front by a deep short canal. The middle lobe of the abdomen and tail is rather longer than the lateral lobes, and is rounded and very prominent throughout. It is composed of 18 articulations, seven of which appear to belong to the tail; it is, however, somewhat difficult to define the length of the tail with precision. The costal arches of the lateral lobes, particularly those near the tail, are bifurcate. Length almost three inches.
The original fossil, from which the cast was taken, is in the New York Museum. I am indebted to Mr. Rubens Peale, the liberal proprietor of that flourishing and important institution, not only for the use of it in this Monograph, but also for some valuable information relating to other species. The precise locality of Mr. Peale's specimen is not known, but in the cabinet of J. P. Wetherill, Esq., there is a fine head of the C. diops which was found in the State of Ohio. Both specimens are mineralized by the same kind of soft grey coloured limestone—and I have but little doubt that they were derived from the same place.
Calymene Macrophthalma.[20] Brongniart. Cast No. 9.
[20] From the Greek for "Great eyes."
Clypeo antice, caudaque postice attenuatis, oculis magnis exsertis.
This species, according to Al. Brongniart, who first described it, is remarkable for the magnitude and protuberance of its eye-shaped tubercles, and by the prolongation of the anterior portion of the buckler, in the form of a snout.
The back is marked by 12 or 13 articulations, which are thicker than those of the tail. The tail is short, pointed, and without expansion.