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20
R. HOEPPLI AND H. J. Chu,
thermal water brought up by a bucket. Temperature of the thermal water down in the well not measured.
Three females, Tangshan near Nanking. Overflow of a hot spring. Water temperature 35° C.
Thirty-four females, Wen Ch'uan near Peiping. Stone tank storing thermal water. Temperature 34° C.
Description:
Males-Length: 0.35 (0.31-0.38) mm.
-28 (25-31). B-4.8 (4.0-5.5). ɣ−3·3 (3.0-3.6).
л-2.
Eight
Cuticle finely striated. Anterior end somewhat flattened. submedial and two lateral setæ, six small papille. The mouth opening has a hexagonal shape, there are no distinct lips. Behind the mouth opening, within the mouth capsule there is a large dorsal tooth and two small sub- ventral teeth. Behind the teeth the pharynx with strongly chitinized walls reaches far posteriad with gradually decreasing diameter. The esophagus has a bulb without valves. The nerve ring is at about the middle of the length of the oesophagus. The oval amphids are near the proximal end of the pharynx. The excretory pore is near the anterior margin of the nerve ring. The equal spicula are 0.02 mm. long. There is only one testis. The tubular outlet of the spinneret is well developed.
Females-Length: 0.47 (0.31-0.51) mm.
-34 (32-36). B-5.0 (4.0-6.1). ɣ-3.8 (3.6-3.9).
n—14.
Vulva slightly in front of the middle of the body. There are two straight ovaries and in all specimens the uterus contained a single egg.
Representatives of the new genus were relatively numerous in our material and occurred in rather different places. The new genus is related to Chromadora and Plectus. It is interesting to observe that in Yellowstone Park (Mammoth Hot Springs, water of atmospheric temperature) a Chromadora species was found (Chromadora nanna Hoeppli 1926) which seems to be rather similar to Greenia orientalis.
Formula of de Man: -14.8. B-43. 8-3·3·
Because the description of Chromadora nanna had to be based on a single rather badly preserved specimen, it is possible that the re-examination of more and better preserved material would show that the anterior end of Chromadora nanna possessses setæ and that this species will have to be placed in our newly created genus
Even if this would be the case, there Greenia. remain sufficient specific differences between Chromadora nanna and Greenia orientalis to justify the establishment of Greenia orientalis as a new species.
The genus Greenia is named after Mr. Roger S. Greene, Acting Director of the Peiping Union Medical College.
Plectus chengmohliangi n. sp.
(Pl. 10, Figs. 4-6).
The Hong Kong Naturalist.
Free-Living Nematodes from Hot Springs in China and Formosa.
21
Diagnosis: Plectus with four submedial and two lateral setæ and two circles of six small papilla at the anterior end.
No males found.
Nine females from Foochow, Ti Yi Lou (First Class Bath House). Wall of a stone tank storing thermal water of 34.5° C.; the walls were cover- ed with a thin layer of alga.
Length: 0.43 (0.41-0.45) mm.
Description:
-20.9 (20.5-21.1). B-3.5 (3.1-3.6). -5.8 (5.2-6.8).
n-9.
Cuticle transversely strited. The anterior end bears two circles of six papillæ cach; the papilla of the inner circle are extremely small. There are four submedial and two lateral rather short seta. The pharynx narrows posteriad; at the connection of pharynx and wsophagus the lumen of the latter shows a small widening. The amphids are round and situated a short distance in front of the posterior end of the pharynx. The nerve ring is located at about the middle of the esophagus. As the posterior end of the @sophagus protrudes as a cone into the intestine, a rather well marked cardia is formed. The vulva has a position at about the middle of the body length; its distance from the anterior end was 0.22 mm. (0.20-0.23). The two ovaries are reflexed, the ends being in the region of the vulva. There is a spinneret with a well-developed tubular outlet.
Piectus chengmohliangi resembles P. armatus Bütschli, 1873 in so far as it has six rather short seta at the anterior end; the main differences between the two species is the presence of two circles of six papilla cach at the anterior end in P. chengmohliangi and the different length of the tail: P. armattus -9.3, P, chengmohliangi 8-5.8.
The new species is named after Mr. Cheng Moh-liang of Foochow who served as guide on the collecting trip.
Microlaimoides lingi n. sp.
(Pl. 11, Figs. 11-13; 12, Figs. 25-20).
Diagnosis: Eight submedial and two lateral setæ at the anterior end. Mouth cavity funnel-like with one small dorsal tooth. Bulb of the œsophagus.......... without valves. Outlet tube of spinneret short. Two equal spicula, a horschoc-shaped telamon and a short straight gubernaculum.
No females found.
Three males, Changchow from two different springs 5 and 13 feet respectively above the surface of the water. Water temperature in the first case 39 C. in the second 48.5° C.
One male, Foochow, Ti Yi Lou (First Class Bath House). Stone tank with water of 34.5° C.
Several larva, Foochow, Wang Tehuang (Wang Settlement). Small wooden tank, walls covered with incrustations. Water temperature 51° C.
Supplement No. 1, 1931.
99