Phylum Onychophora (Velvet Worms)
Approximate Number of Species: 110
Largest: Peripatidae sp at a length of 8.66 inches (220 mm)
Smallest: Ooperipatellus sp at a length of 0.39 inches (10 mm)
References:
Monge-Najera J (1994) Reproductive trends, habitat type and body characteristics in velvet worms (Onychophora). Revista de Biologia Tropical 42(3):611-622.
H. Ruhberg, personal communication
Brusca RC & Brusca GJ (2003) Invertebrates (Sinauer Associates, Inc., Publishers, Sunderland, MA) 2nd Ed.