would apply probably equally well to several species. In the absence of any type, it has seemed better to apply the name somewhat empirically, rather than to discard it altogether.
As far as I can determine, P. Virginiensis of Saussure is not the species here recognized, but represents rather the two species trimaculatus and corrugatus combined, both of which he appears to have had.
Hab. Middle States.
P. corrugatus.
P. atro-castaneus, scutis fulvo postice marginatis; laminis lateralibus fulvis, latissimis; scuto anale triangulare, elongato, postico fulvo, apice truncato; appendicibus masculis maximis, spinulo laterale robusto subbreve vix curvato armatis; spina terminale maxima, robusta, compressa, tortuosa, spinulo basale armata. (Fig. 50.)
Blackish-chestnut; scuta margined with fulvous posteriorly; lateral laminæ yellowish, very broad; anal scutum triangular, elongate, posteriorly yellowish; its apex truncate; male appendages very large, armed with a rather short, robust, scarcely curved, lateral spinule; terminal spine very large, robust, compressed, tortuous, armed with a basal spinule.
P. corrugatus, Wood, Proc. Acad. Nat. Sci., 1864, p. 6.
| Fig. 50. | Fig. 51. |
 | |
The color of the perfect animal is a chestnut-black, rarely reddish chestnut, with a moderately broad margin of fulvous [in alcoholic specimens] on each scutum. This band may be red during life. The scutæ beautifully polished to the naked eye, the microscope shows to be obsoletely wrinkled. Very many of these wrinkles are longitudinal. The head is of the same color as the body; medianly it is distinctly sulcate; interiorly it is broadly and rather deeply emarginate. The scutal side plates are fulvous above and below. Their anterior angles are rounded, their posterior more or less acute, and in the hinder ones prolonged. The under surface of the body is of a light yellow. The male genital appendages are very large and robust. They have a short, slightly crooked spinule attached and lying close to their side. The terminal spine is irregularly spiral, and has near its base a curved spinule. At the point of its origin is a tuft of bristly hairs. Each female appendage (Fig. 51) is chiefly composed of a short, almost globular, scarcely at all pilose process, in one side of which there exists a large opening. Through the side opening projects a pair of large, thick plates, fitting together somewhat in the manner of bivalve shells. These nearly equal in height the main process. The spine on the second joint of the feet is robust, but acute. The whole animal is about one and a half inches in length.
Hab. Michigan.—Prof. Miles.—Trenton Falls, New York. Mus. Comp. Zoology.—D. Mack.
