340 REPORT—1885. 
median line of the valve ; but this and other features were varied by age 
and sex, and have been modified by pressure in the different specimens. — 
The antero-ventral margin is sometimes indrawn, making the point in 
front more acute. The hinder margin is truncate with an elegant ogee 
curve, full below, and ending above in the postero-dorsal angle, often 
but not always sharply defined. In some cases the ventral margin is 
much deeper than in others. Some fragments of carapaces from Leint- — 
wardine (Ludl. Mus. O., and M. P. G. 23) are ornamented with longitudinal 
lines or strie of varying strength. 
Seven abdominal segments are usually exposed. 
Good specimens of C. Murchisoni (Agass.) :— 
M.P.G. x 1.—Carapace, 125 x 55 mm., withacute prow. Smooth, longitudinal linear 
ornament. Long form of carapace. Leintwardine. 
M.P. G. x +.—Carapace, 60x 28 mm. Smooth and glazy. 
Seven segments, about 50 mm. (the last one about 20 mm.) Telson 
crushed. Long form of carapace. Leintwardine. 
Ludl. Mus. D.—Carapace, 50x 30 mm. Smooth. 
Seven segments, 55 mm. (the last one 20mm.) Some with straight 
strize. 
Telson imperfect. Short form of carapace. Leintwardine? 
Ludl. Mus. B.—Carapace, about 50x 30 mm. Short form of carapace. : 
Exposed segments (crushed up), 50 mm. With straight, wrigely — 
strive. 
Telson broken. Leintwardine. 
M. P. G. x 3.—Carapace, 40 x 20 mm., with acute prow. Smooth and glazy; rough 
at the place of the teeth. 
Five? segments, about 30 mm. Long form of carapace. Leint- 
wardine. 
M. P. G. x 3.—Carapace, 25x11mm. Small, smooth, sharp in front, marked by 
teeth inside. 
Seven? segments, 28 mm. (the last one 14 mm.) Linear ornament. 
Telson, 25 mm. Ridged and pitted (spines). (Stylets about 12 mm, 
Ridged.) Long form of carapace. The whole animal 3} inches in ~ 
length. Bow Bridge, near Ludlow. 
Ludl. Mus. A.—Carapace, 24x13 mm. Small, smooth, subovate, sharp in front. 
Seven segments, 30 mm. (the last one 12 mm.) Longitudinally 
striate. 
Telson imperfect (12 mm. preserved). Medium form of carapace. 
Leintwardine ? 
Oxford Mus. J, K, and Q.—Small individuals in the Grindrod Coll. from the Lower 
Ludlow, with features corresponding with those of C. Murchisoni. 
K is a carapace especially agreeing in form, though measuring only 
15x6mm. J isstill smaller; it is much crushed, and about 8 x 4 
mm., with an abdomen of 6 segments, probably imperfect, 9 mm. 
In Q the carapace (18 x 10 mm.) has been misshaped by pressure; 
the abdomen was about 7 mm.; and the little telson was strongly 
ridged, and at least 10 mm. long. 
Addendum. 
1853. Dithyrocaris Murchisoni (Agass.), Geinitz. ‘ Verstein. Grauwackenformation in 
Sachsen,’ u.s.w. Heft ii. p. 24, pl. 19, fig. 13. 
1866. Ceratiocaris Murchisoni, Jones. ‘ Ann. Mag. Nat. Hist.’ ser. 3, vol. xviii. p. 40. 
This is the distal end of a tapering, costulate telson (or stylet ?), and is 
quite comparable with O. Murchisoni (Agassiz), as indicated by Dr. H. 
B. Geinitz. It was obtained from the Silurian Grauwacké beds of the 
Gunzenberg, between Méschwitz and Pohl, near Plauen, together with 
Graptolites, Orthoceras, and Pterinea. i. 
