 Fig. 39. Pterygotus (Pterygotus) carmani, n. sp., paratype, PE5110; ✕ 3.5. Part of gnathobase of coxa of swimming leg. Ruled line, one centimeter. |
 Fig. 40. Gnathobase of coxa of swimming leg of Pterygotus (Pterygotus) carmani, n. sp., paratype, PE5109. Shading indicates preserved patches of test. Ruled line, one centimeter. |
and 2.7 mm. in width. The incomplete structure in figure 39 (specimen PE5110) is 21.5 mm. in width.
The gnathobase of the coxa of one of the walking legs (PE5113) measures 17 mm. in width; it bears at least 18 teeth, of which the second tooth is the largest and measures 5.5 mm. in length. The teeth are slender and pointed and become exceedingly slender in the posterior part of the gnathobase.
The metastoma is represented by a single specimen (PE5112 a and b) in which the posterior third is missing. It is an ovoid-cordate plate, deeply indented on the anterior margin and reaching its greatest width slightly anterior to the midsection. It is covered with large scales, more prominently developed on the anterior part. The metastoma is 41.0 mm. in greatest width with an estimated length of 55.0 mm. (see fig. 41).
The mesosoma is undoubtedly represented by many of the fragments found throughout the black shale but these cannot be determined as belonging certainly to P. carmani. Another pterygotid, P. (Erettopterus) serratus, which has similar ornamentation, is asso-
