Leg formula
The leg formula is used in arachnology for a simplified description of the leg length of spiders as a determination aid. The four pairs of legs are usually numbered with Roman numerals from front to back and indicated in the order of decreasing length:
- "I, IV, II, III" is the leg formula for Chilobrachys huahini Schmidt & Huber , 1996, a tarantula from Thailand .
- Norman I. Platnick gives the leg formula for the genus Segestrioides as "1423".
However, the length of the pedipalpe is also included in the determination; often also the scopula of the tarsi, the hairiness and thorns of the leg links femur , patella, tibia, metatarsus, tarsus .
Table: Limbs in mm of Chilobrachys huahini
| Femur | patella | Tibia | Metatarsus | tarsus | overall length | |
|---|---|---|---|---|---|---|
| Pedipalps | 13.5 | 8th | 10 | - | 9.5 | 41 |
| Leg I. | 20th | 11 | 11 | 14th | 8th | 71 |
| Leg II | 18th | 10 | 13 | 11 | 8th | 60 |
| Leg III | 14th | 9 | 11 | 12 | 8th | 54 |
| Leg IV | 20th | 10 | 15th | 16 | 9 | 70 |