Echinorhynchus gigas, Goeze, 1782.
Syn.: Tænia hirudinacea, Pallas, 1781.
Fig. 348c.—Egg of Echinorhynchus gigas. 300/1. (After Leuckart.)
The body is elongated, gradually decreasing in thickness towards the back. The rostrum is almost spherical, and is beset with five or six rows of recurved hooks. The males measure 10 to 15 cm. in length, the females 30 to 50 cm.; the eggs are provided with three shells, of which the middle one is the thickest. The eggs measure 0·08 to 0.1 mm. in length. The giant Echinorhynchus occurs especially in the intestinal canal of the domestic pig; it is less common in other mammals. It bores deep into the mucous membrane with its rostrum, and causes an annular proliferation around the perforated spot; occasionally also it causes perforation of the intestine.
It is doubtful whether the giant Echinorhynchus occurs in man. Leuckart admitted that there were a few positive cases. According to Lindemann, Ech. gigas occurs in human beings in South Russia, and its presence is not rare. This statement, however, has not been confirmed. Its presence in man is by no means impossible, as its intermediary host, the cankerworm, or cock-chafer (Melolontha), is, according to Schneider, occasionally eaten raw by human beings. According to Kaiser, the golden beetle (Cetonia aurata) and, according to Stiles, another beetle in America (Lachnosterna arcuata) are also intermediary hosts.
Echinorhynchus hominis, Lambl, 1859.
This term is applied to an Echinorhynchus found by Lambl in the intestine of a boy who had died of leucæmia; the worm was 5·6 mm. in length, and the almost spherical head was beset with twelve transverse rows of hooks.
Echinorhynchus moniliformis, Bremser, 1819.