PLATE XXIX. 
Echinocakis punctata. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
See Plates 27 and 28. 
1. An enrolled individual of average size, having the carapace somewhat compressed, but showing 
the position of the optic spots (e), the number and disposition of the nodes, a well-defined nuchal 
furrow and the tubercles along the posterior portion of the hinge-line. A single caudal spine 
is seen projecting from beneath the antei-ior portion of the carapace. 
2. Profile view of the same, showing a portion of the enrolled abdomen. 
Hamilton group. Pratt's Falls, Onondaga county. 
3. A neai-ly entire individual, showing the valves of the carapace fully expanded and the six abdom¬ 
inal somites, which are detached fi-om the carapace. The caudal parts are missing and are 
restored in outline. 
Hamilton group. Pratt’s Falls, Onondaga county, 
4. A specimen showing the post-abdomen and a portion of the internal surface of the last two somites 
of the abdomen. 
Hamilton group. Pratt's Falls, Onondaga county. 
5. An expanded carapace covei'ed with individuals of Piscina media. Hall, not an infrecpient mode of 
occuri’ence at this locality. 
Hamilton group Pratt’s Falls, Onondaga county. 
6. A portion of the surface of the cai'apace represented in plate 28, fig. 2, enlai'ged to two diameters 
to show the character of the ornamentation between the carina and the ventral margin. The 
specimen is a cast of the internal surface, and shows the strong punctse which become still moi-e 
conspicuous near the lower edge of the cai-ina, and the elevated, undulating lines i-adiating fi-om 
the carina. Upon the upper surface of the test the ornamentation is distinctly pustulose and 
the radiating lines ai-e scarcely visible. 
Hamilton group. Fahius, Onondaga county. 
7. An imperfect specimen, showing the inteimal surface of the left valve of the largest carapace 
observed. In the cephalic region thei-e lies a single lai-ge mandible which shows no denticles, 
but bears a conspicuous manubrium. The posterior margin of the valve bears three strong 
tubei-cles, a feature usually but faintly developed in smaller individuals. 
Hamilton group. Vinegar Brook Grlen, Cayuga Lake. 
8. A large right valve, showing normal proportions and the position of the optic spot, but wanting 
the elevated lines on the ventral surface and the postei'ioi' mai-ginal tubercles. This is the type 
specimen of Ceratiocaris? jgunctata. Hall, and was oiiglnally figured with a conspicuous node 
near the j)Ostei-ioi- extremity of the hinge-line; this, however, has proven to be a portion of the 
matnx. 
Hamilton group. Cayuga Lake. 
Echinocakis pustulosa. 
Page 178. 
Fig. 9. The type specimen ; a i-ight valve showing the number and disposition of the nodes, the character 
of the carina and the strong pustules upon the surface of the nodes. A portion of the cephalic 
region is broken away and is j'estored in outline. 
Fig. 10. The same, enlarged to two diameters. 
Erie shales. (Portage group.) Paine's Creek, Lake county, Ohio. 
