PEESIDENl's ADDRESS. 245 



India, has not yet been by any means exhausted, especially as concerns 

 the minute forms, such as Pupa, Acmella, Paludesirma, etc. These 

 live on the moist green surface of the rocks, or on the mossy ledges, 

 but only during the rains. When I tell you that from the neighbour- 

 hood of one place, Cherra Punji, I only succeeded in finding two such 

 species, and one of these I sought for in vain a few years afterwards, 

 how many must remain to be discovered in the successive deep gorges 

 east and west of Teria, 130 miles on one side to the Garo Hills and 

 150 miles to the Naga Hills on the other. The heat, the drenching 

 rain, the necessary exposure, and the insalubrity of some of these 

 valleys ■ during the summer months render them almost inaccessible, 

 except to a most keen and strong collector. The rainy season is also the 

 best time for seeking the slug-like forms, of which several must remain 

 to be discovered. Such a form lives on the south end of the Cherra 

 Plateau, near the great cave. One day in the month of June, when 

 with a party of Khasias forcing our way through the dense scrub to 

 the mouth of the cave, I took off a leaf a slug of a geniis which I had 

 never seen before. During the transfer to a box it was dropped into 

 the undergrowth, and could not again be found, and although further 

 search was made as we proceeded, I never succeeded in finding another. 



How often it is that species one year most abundant are not 

 obtainable the next. Benson's account of the discovery in 1842, at 

 Moradabad, of Camptoceras terebra is a good example ; in 1843, in the 

 same piece of water which had once formed the bed of the Kam Ganga 

 River, only three specimens could be found; in 1845 none could be 

 seen at all. This genus was not again met with until 1869, when 

 I discovered one morning in a marsh in the Maimensing District, near 

 the base of the Garo Hills, not only one, but two species, which 

 were described by Henry Blanford as C. Austeni and C. lineatum. 

 This spot is 760 miles from Moradabad. No one has ever taken them 

 since, yet the genus must be, I feel convinced, a common one, of 

 which other species probably will some day be discovered. It is still 

 more interesting to relate that this genus, so little known even at the 

 present time, was found fossil by Mr. Shrubsole about 1880, in the 

 Eocene beds of Sheppey, and the species was identified, described, and 

 figured by me as C. priscum. This is a remarkable fact in the 

 distribution of a genus in time and area. With such a gap to bridge 

 over it should make us very careful in drawing conclusions regarding 

 the original development and course of distribution of animal life, and 

 its range in time. We have to bear in mind as well the extreme paucity 

 of the material we have to work with, limited to so few genera, no 

 fossil evidence at all in the majority of them. 



This leads me to draw attention to the work that yet remains 

 to be accomplished, not only among living forms, but their 

 fossil predecessors, and how little has yet been effected. Take, 

 for example, the mammalian fossil beds of Miocene and Pliocene 

 age, perhaps better known as the Siwalik Series, tilted and faulted, 

 compressed against the base of the Himalayas, and skirting the 

 Sulaiman Range to Baluchistan. These beds are of enormous 

 thickness, and present in places land surface after land surface, 



