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one, yet it must be far below the actual total. The Mammals, 

 Birds, Reptiles and Mollusca, cannot be very much increased, 

 if at all, but the Insecta with further research will perhaps 

 be more than doubled. For not only are the figures of the 

 Lepidoptera and Coleoptera by no means complete, but the 

 great orders of Hymenoptera, Diptera, Hemiptera, and Orthop- 

 tera have as yet few or no records. It will be noticed too, 

 that there are no records of Spiders, Land Crustaceans, 

 Earthworms, and other low forms of animal life, but which 

 if the species could be enumerated would still further swell 

 the total. Taking everything into consideration, it may 

 be roughly estimated, that between four and five thousand 

 species of animals inhabit Cleveland to-day. 



This fauna can be classified according to the status of the 

 various species composing it, viz. : — 



Introductions by Man. 

 Accidental Stragglers and Visitors. 

 Irregular Visitors. 

 Regular Visitors. 

 Resident Species. 



This classification, as we shall see further on, provides a 

 partial solution to the manner in which animals, now resident, 

 may have entered the district. Neglecting, therefore, the 

 various classes of visitors for discussion in the next section, let 

 us devote some attention to the residents, since these offer 

 many suggestive problems for investigation. 



Though the highest point of Cleveland, on Una Moor, is 

 but 1,489 feet, still many interesting facts illustrate the 

 altitudinal range of local animals. Thus, the Mole, the Angles 

 Shades Moth (Phlogophora meticulosa), and the Black Slug, 

 ascend from sea-level almost to the highest watershed. I 

 have noticed the Mole on grassy moorland -lopes, at 1,200 

 feet, near Ralph Cross, Castleton ; the Moth (essentially a 

 lowland species not dependent on ericetal plants for its food, 

 and therefore a straggler to the uplands), on the promenade 

 at Saltburn, and on Kildale Moor (1,000 feet) ; whilst the 

 slug {Avion aier) can often be seen crawling on the peaty soils 

 of the hills. The Mole, however, appears to be absent from 

 the true heather moors, perhaps owing to the general 



