. Fresh-water biology. Freshwater biology. PARASITIC ROUNDWORMS 541. 21 (i8) No conical spicules behind cloacal aperture; caudal lobes cylin- drical Gordius platycephalus Montgomery 1898. For female of this species consult 30 in this key. Male up to 216 mm. long, 1 mm. broad. The flattened anterior end is characteristic, but Montgomery found one specimen apparently of G. densareolatus with this feature and could explain it only as a hybrid form. Canada, Pennsyl- vania, and Guatemala. Fig. 842. Gordius platycephalus J; head and tail in ventral aspect. Magnified. (After Montgomery.) 22 (11) Caud
. Fresh-water biology. Freshwater biology. PARASITIC ROUNDWORMS 541. 21 (i8) No conical spicules behind cloacal aperture; caudal lobes cylin- drical Gordius platycephalus Montgomery 1898. For female of this species consult 30 in this key. Male up to 216 mm. long, 1 mm. broad. The flattened anterior end is characteristic, but Montgomery found one specimen apparently of G. densareolatus with this feature and could explain it only as a hybrid form. Canada, Pennsyl- vania, and Guatemala. Fig. 842. Gordius platycephalus J; head and tail in ventral aspect. Magnified. (After Montgomery.) 22 (11) Caudal end straight, not enlarged nor lobed. (Females of Gordius) . 23 Compare 5 in key. 23 (24) No elevated cuticular areoles on surface of body. Gordius villoti Rosa 1882. For male and range of this species consult 14 in this key. Largest female 703 mm. long, mm. broad. One variety (G. mlloti difficilis Mont- gomery) has cuticular areoles at the ends of the body only. The other varieties are Uke the males marked with light spots or plain. Montgomery found some points of difference from the European type, and the American form may prove on further study to be a separate species. 24 (23) Elevated cuticular areoles cover the entire surface of the body. 25 25 (26) Paired dark stripes occur in median hues. Gordius leidyi Montgomery 1898. Male of this species is unknown. Female 295 mm. long, mm. broad. Sharply dis- tinguished from all other species in the genus by the pecuhar truncated form of the posterior end and the two narrow parallel stripes of intense reddish brown in the median line of the dorsal groove. In the Leidy collection; source unknown. Fig. 843. Gordius leidyi ^ ; head and tail in dor- sal aspect. Magnified. (After Montgomery.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Bald
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
