Page:Wood 1865 - The Myriapoda of North America.djvu/62

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THE MYRIAPODA OF NORTH AMERICA.
197

of a long, very slender, almost setiform process, and a shorter straighter one. The former at its base is bent at right angles to itself; and distally it is somewhat spirally arched over the other.

Fig. 26. Fig. 27. Fig. 28. Fig. 29.

The female (Fig. 29) appendages consist of two broad, robust, pilose processes, with a pair of very slender, almost filiform, feet-like bodies, springing from their conjunction and equalling them in length. The major portion of each appendage is composed of a single plate. This is folded on itself, so as to constitute an irregular, flattened cylinder, which is open at its end and along the outer edge. It presents on one aspect an unbroken, tolerably regular surface, but on the other is proximally abbreviated. Through the opening thus afforded projects a pair of subcircular, somewhat globose plates, fitting together much as the shells of a bivalve. The filiform processes are on the former surface. Length, 2 inches.

Hab. Illinois. Smithsonian Institution.—R Kennicott. Georgia. Coll. A. N. S.—Dr. J. L. Le Conte, U.S.A.

Fig. 30
In the Kennicott collection I have seen a male Iulus very closely resembling the former, but differing so much in its genital appendages that it probably represents a distinct species. The outer of the two parts, forming each appendage, consists of a thin, flat, crooked, very irregular process, and a shorter, robust, pilose, and strongly clavate one. The former, proximally, is quite broad, and narrows from the base, but distally is but at a right angle to itself, and is rapidly contracted, so as to terminate in a nearly cylindrical crooked point. The main process (Fig. 30) of the inner portion is somewhat cylindrical proximally, but is distally expanded. At first bent at a right angle to itself, it next has the swan-neck curve, and is then bent at an acute angle to itself to be straight the remainder of its length. At this angle there is a minute sharp spine. Shielded, as it were, by this process, there is another, very slender and acute.

It is most probable that I. venustus, Wood, is the species intended to be indicated by Mr. Say under the name of impressus, although his description is so meagre that it could be applied to other species. The locality would seem to fix it, however. Mr. Say's description is given below in full.

" Brown, a series of lateral black dots, beneath yellowish white; ultimate segments mucronate."

66 Body cylindrical, emarginate, above brownish, beneath yellowish white, appearing glabrous; segments each with a lateral black spot, whitish lines and dots sometimes obso-