CRUSTACEA. 267 



annulations, which are separated by broad, shallow grooves. Surface ornamentation 

 consisting of two rows of tubercles which become obseolete on the last three or four 

 posterior annulations. Lateral lobes with 12 pleura which slope obliquely to the lateral 

 margins, the 7 or 8 anterior ones divided by distinct longitudinal furrows which persist 

 to the end of each rib; extremities of ribs flattened to form a marginal border having a 

 uniform width of 2 mm., intervening .furrows broad. Surface marked by indistinct 

 pustules. 



Cephalon and thorax unknown. 



Remarks — The form resembles Dalmanites multiannulatus Ohern, from the Mary- 

 land Oriskany, but is smaller, has fewer axial and pleural segments, less distinct sur- 

 face ornamentation, and it is especially characterized by the presence of a caudal 

 spine. 



Horizon — Lower beds. 



Holotype No. 27535, Walker Museum. 



Name — This fossil is named after Mr. A. W. Slocom, of Walker Museum, Uni- 

 veristy of Chicago. 



Dalmanites cf. stemmatus var. convergens Clarke 



Plate 71, figure 17 



1892. Dalmanites sp. nov. A. var., Amer. Jour. Sci. 1892, p. 412. 

 1900. Dalmanites (Synphoria) stemmatus var. convergens Clarke, Mem. N. Y. State, 

 Mus., vol. 3, No. 3, p. 19, pi. 2, figs. 3-5. 



Description — Pygidium triangular, slender and tapering, width greater than length. 

 Axial " region with 12 flattened annulations, the posterior two scarcely discernible; 

 intervening grooves narrow; pleural segments 10, each one divided by a narrow, faintly 

 defined median furrow. Lateral margins gradually converging posteriorly, apparently 

 terminating in a short caudal spine. 



Remarks — A single incomplete pygidium resembles the above species. The only 

 difference observed is the presence of the faint median grooves on the pleural segments. 



Horizon — Upper beds. 



Figured specimen No. 27539, Walker Museum. 



Dalmanites sp. undet. 

 Plate 71, figure 18 



There is present in the collection a single specimen of the frontal margin of an 

 unknown species of Dalmanites. The outer edge is coarsely denticulate, with 7 or 8 

 serrations, the two central ones being larger than the others. A resemblance is noted 

 with the frontal margin of Dalmanites multiannulatus Ohern, but the Little Saline form 

 is smaller, more evenly dentated, and the bifurcating process is less conspicuous. 



Horizon — Lower beds. 



Figured specimen No. 27537, Walker Museum. 



Dalmanites praenuntia sp. nov. 



Plate 71, figure 19 



Description — Pygidium of medium size, broadly triangular in outline. The dimen- 

 sions of the holotype are: Length 14 mm., width 20 mm. Axis attenuate, depressed 

 convex, marked by 12 to 14 annulations; intermediate furrows narrow arid shallow. 

 Lateral lobes with a corresponding number of ribs also separated by shallow furrows, 

 each rib divided longitudinally by a fine median groove which bends posteriorly as it 

 approaches the dorsal furrow. At the lateral margins the ribs are slightly flattened 



