2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 75 



mountainous ranges reaching into Burma in a north and south direc- 

 tion from the Himalayas. This portion of the country consists of 

 broad, undulating table-lands, rolling downs, and alluvial plains — 

 including the deltas of the Irrawaddy and Sittang Rivers, and the 

 valleys of the Chindwin, Mu, Sittang, and Irrawaddy Rivers. The 

 delta of the Salween River may conveniently be included in this 

 region. With the exception of the Pegu Yomas which separate 

 the valleys of the Irrawaddy and Sittang Rivers, the land is less 

 than a thousand feet above the level of the sea. Most of the culti- 

 vated land is within this region as well as a very large proportion 

 of the population. 



That portion of the country commonly called the "Hills" may be 

 designated the Peripheral Hill region. This section of the country is 

 largely over a thousand feet above sea level, with considerable areas 

 above the 3,000-foot level, and walls off the central basin region from 

 the rest of Asia. The mountains of the western limb of this periph- 

 eral region pass, with interruptions by the sea, through the Andaman 

 and Nicobar Islands, Sumatra, Java, and New Guinea. Similarly 

 the mountains of the eastern limb pass southward, through a small 

 portion of Siam and the Malay Peninsula. On the western slopes 

 of the Arakan and Tenasserim Hills are narrow coastal strips much 

 broken up by the sea. There are numerous islands off both coasts, 

 those west of Tenasserim constituting the Mergui Archipelago. The 

 Peripheral Hill region is sparsely inhabited and covered with jungle 

 of varying density except on the grassland plains of the Shan 

 Plateau. 



HISTORICAL CONSIDERATIONS 



Our knowledge of the Oligochaete fauna of the Province of Burma 

 has been based almost entirely on the study of museum specimens 

 incidentally obtained by collectors who were primarily interested in 

 other groups of animals. As might be expected, under these circum- 

 stances references in the literature to Burmese forms are rather 

 scarce. The first significant contribution ^ was a series of three papers 

 by Daniele Rosa in the Annals of the Civic Museum of Genoa, Italy, 



■Actually the first record of an earthworm from Burma is a description of Perionyx m'intoshi from 

 Akyab published in 1883. The species was founded for a single immature worm. Some years later 

 Beddard (1S92) described more completely under the same specific name mature worms obtained from 

 India, but indicated doubt as to the identity of the Burmese and Indian forms by prefixing, in the syn- 

 onymy, the original reference with an interrogation mark. ("My observations upon Perionyx m'intoshi 

 were made upon a single, not sexually mature, example; they were therefore not quite conclusive as to 

 the distinctness of the species.") Michaelsen omitted Burma from the habitat of this species in his list 

 of 1908. Stephenson, on the other hand, included P. m'intoshi in his list of Burmese forms. The spe- 

 cific identification of immature earthworms is notoriously difficult and is not usually attempted by sys- 

 lematists. In view o f this difficulty and the distance between the Burmese and Indian habitats it hardly 

 seems wise at the present time to attach any particular importance to Beddard's record. 



