128 KANSAS UNIVERSITY QUARTERLY. 



Myalina? exasperata, n. sp. Plate XXXII, Fig. 4. 



Shell cuneate-ovate in outline, beaks pointed, terminal, shell 

 very thin, apparently composed of a single layer, compressed, 

 valves nearly or quite equal. The anterior? margin nearly straight 

 above, and merging into the narrowly rounded ventral region; the 

 posterior? region similar to the anterior, but more oblique. The 

 surface is granular and marked by indistinct, rather broad, concen- 

 tric stritC. 



Measurements: Height, 43 mm.; length, 28 mm.; convexity, 3 

 mm.; length of hinge about 29 mm. 



Several specimens of this shell have been collected from the coal 

 mines west of Topeka, Kansas. 



This shell has been known for several years from the above 

 locality, though the extreme thinness of the sh<^ll and the softness 

 of the shale in which it occurs makes it almost impossible to col- 

 lect good specimens of it. 



The hinge of this shell is not sufficiently well shown to permit of 

 its proper classification. It is left in JSlyalina for the present, for 

 want of better information concerning its beak and muscular im- 

 pressions. The extreme thinness of the shell makes it very prob- 

 able that it does not belong to that genus. 



Somphospongia, n. gen. 



A globular to mushroom-shaped calcisponge, attaining a large 

 size, and generally possessing a somewhat spherical-shaped cloaca 

 near the base, the inhalent and exhalent canals too similar to be 

 distinguished, all very irregular and crooked, distributed over the 

 entire surface and moderately large; there is a thick dermal layer 

 covering the entire animal, which was free, apparently resting with 

 the base in the mud in the adult stage. 



Somphospongia multiformis, n. sp. Plate XXXIII, Figs, i to 10. 



Small to very large sponge varying in form from globular to 

 mushroom-shaped, free, and gregarious. Connecting with the 

 cloaca there is an irregular, branching, canal system which com- 

 municates with the exterior over the whole surface, though in the 

 larger specimens they seem to be smaller and probably nearly use- 

 less at the base. These canals are very irregular in shape, and, when 

 viewed on the surface, appear to be labyrinthine; they become 

 smaller as they proceed inward toward the cloaca and less numer- 

 ous. When unweathered the entire sponge is covered with a mod- 

 erately thick dermal layer, the folds of which form the walls of the 

 canals. There is no sign of attachment in any of our specimens, 



