450 SYSTEMATIC PALEONTOLOGY 



Haeckel described this species as follows : — 



" Each pileated piece of the skeleton stirrup-shaped, with two pairs 

 of meshes, and a square basal ring, the four corners of which are pro- 

 longed into four perradial spines. Between the latter four interradial 

 beams arise from the sides in pairs, and the two pairs are connected by 

 a diagonal arch. Therefore the two opposite meshes are larger and pen- 

 tagonal, the otlier two meshes (alternating with these) are smaller and 

 square. No vertical spine on the apex. 



"Diameter of the basal square ring (diagonal) 0.01 to 0.02, of the 

 meshes 0.005.'' 



A single specimen of this species has been found in Maryland. 



Occurrence. — Calvert Formatiox. Cambridge Artesian Well (193 

 to 335 feet). 



Collection. — Johns Hopkins University. 



Suborder NASSELLARIA. 



Superfamily CYRTOIDEA. 



Family LITHOCAMPIDA. 



Genus LITHOCAMPE Ehienberg. 



Lithocampe marylandica n. sp. 

 Plate ex XX, Fig. 4. 



Description. — Shell smooth, hyaline, spindle-shaped, with four dis- 

 tinct joints and a constricted month; joints of different lengths 

 = 7: 10: 12 : 34; third and fourth joints nearly equal in breadth; pores 

 large, somewhat irregular in size and shape; three rows of pores in each 

 of the first three joints, and seven rows in the fourth joint. 



Occurrence. — Calvert Formation. Lyons Creek. 



Collection. — Maryland Geological Survey. 



Genus EUCYRTIDIUM Ehienberg. 

 EUCYRTIDIUM calvertense n. sp. 



Plate CXXX, Fig. 5. 



Description. — Shell smooth, spindle-shaped, with five joints (and 

 possibly a sixth broken away) ; cephalis subspherical, with a very short 



