STUDIES ON THE EARTHWORMS COLLECTED DURING THE DAPHABUM EXPEDITION IN ARUNACHAL PRADESH, INDIA

The Daphabum Scientific Expedition was organised by the Geological Survey of India in November, 1969 January, 1970 to explore the Lohit District of Arunachal Pradesh-. The general topographyof the area is of mighty mountains, intersected by large river beds and water courses. The vegetation at lower altitudes consists of tall trees, shrubs, bamboo, cane, wild banana and various kinds of creepers. At higher altitudes, the forest is mostly composed of ferns and rhododendorons. The average annual rainfall is over 300 cm., mainly occurring from April to October. The climate is quite -hot in summer with the temperature reaching upto 30°C, and very cold in winter with the temperature varying from BOC to 17°C and falling below the freezing point at higher elevations during night.


INTRODUCTION
The Daphabum Scientific Expedition was organised by the Geological Survey of India in November, 1969-January, 1970 to explore the Lohit District of Arunachal Pradesh-. The general topographyof the area is of mighty mountains, intersected by large river beds and water courses. The vegetation at lower altitudes consists of tall trees, shrubs, bamboo, cane, wild banana and various kinds of creepers. At higher altitudes, the forest is mostly composed of ferns and rhododendorons. The average annual rainfall is over 300 cm., mainly occurring from April to October. The climate is quite -hot in summer with the temperature reaching upto 30°C, and very cold in winter with the temperature varying from BOC to 17°C and falling below the freezing point at higher elevations during night.
An antero-posteriorly compressed papilla slightly protrudes through th~ second~ry Inala pore. There is a deep depression on the posterior face of the papilla and within this depression is a thin-walled, translucent, tubular penial body, at the tip of which is located a minute male pore. Female pores. minute, on 11/12, close to B lines.
Genital markings, median, unpaired, small, circular In outline, presetal on VI-XII or VI-X, XI or IX-XII. Testis sacs, alnlost entirely in X, with only a slight protuberance in IX, and slightly constricted by 9/10. Vas deferens, slender, closely coiled into a small mass, which is smaller than the testis sac. Vas enteres into the parieties at B levels and runs a little posterior below the longitudinal muscle layer to 0 pen at the anterior end of the prostate. Prostates, muscular, circular in outline, dome-shaped, partially embedded in the parieties. Spermathecal ampulla, ovoid; duct, muscular, thick, shining and loosely coiled on the posterior face of 7/8, slightly enlarged at its ectal end, which is embedded in the parietles.
Genital marking glands, pear-shaped, muscular, embedded in the parieties, below the nerve cord.
Vas deferens, drops ventrally, median to heart and after making a long hair-pin loop upto the base of testis sac, passes under the extraoesophagael trunk, entering the parieties at AB muscular gap. After the removal of a thin nluscular layer, the vas has been traced running to the base of antero-posteriorly compressed, erect prostate. It runs upwards along the inner margin of prostate to open at the ental end of the latter. The vas deferens is enclosed in a common sheath of the prostate.
Spernlathecal duct, muscular, thick ,drops down into 3 or 4 100s8 coils before entering the posterior face of 8/9 septum, then running diagonally in the muscular layer of the septum, enters the parieties at CD.
Remarks.-In one specimen, there is an extra eye-like demarcated area with a minute pore, a little dorsal to the right spermathecal pore. The ovisacs are without any trace of ova, This species has been recorded earlier only from Burma.
Seminal vesicles of X smaller than those of XI. Prostates, extend through XVII-XVIII. Prostatic duct, In uscular, arises from near the anterior end of prostate and after forlIling two zig-zag loops, runs straight into the parieties under an ovoidal thickening, below the nerve cord. The removal of the nluscular layer of the ovoidal body reveals a pear-shaped, sac-like structure, near the ectal end of which, the prostatic duct opens.
Male genital shield, extends acrossXVII and posterior part of XVI.
Male pores, large, in setal zone, on XVII, in AB, connected by a deep transverse groove, which continues outwards, on either side, a .little beyond B and then turns forwards as seminal grooves" extending upto the middle of posterior half of XVI. Seminal 'grooves, straight, deep. Two transverse furrows, a deep and a shallow, are present anterior to male pores in the space between the seminal grooves.
1\11 eronephric, exonephric, in posterior segments there are in addition enteronephric nephridia on the dorsal side of intestine, a cluster of micronephridia in VI near 5/6. Dorsal blood vessel, continued anteriorly onto pharyngeal bulb. Supra-oesophageal, unrecognisable anterior to 10/1'1, in _XI turning off laterally to pass into the calciferous glands. Extra-oesophageals, pass posteriorly into calciferous glands of XII. Latero-parietals, recognisable from XVI anteriorly to 12/13, where they move up to pass into calciferous glands of XII. No subneural. Last hearts, in XII. Holandric. Selnin al vesicles, in X, XI, on the posterior faces of 9/10 and 10/11. Prostates, strap-shaped, extending through XVI-XVIII. Prostatic duct, white, muscular with a little shine, forms a loop near its origin, and then runs straight underneath a well-developed, nluscular, ovoidal body, in XVII, below the nerve cord.
Spernlathecal alnpulla, round; duct, clearly marked off, narrows towards the ectal end, three tilnes as long as ampulla, forming a loop, two limbs of the loop eonnected by tissue; diverticulum, smaller than ampulla, stalked, club-shaped, on the anterior-face at the ectal end of duct.