DOI: 10.5061/dryad.tk0b8
title: Data from: A new species of Illacme Cook & Loomis, 1928 from Sequoia National Park, California, with a world catalog of the Siphonorhinidae (Diplopoda, Siphonophorida)

description: Members of the family Siphonorhinidae Cook, 1895 are thread-like eyeless
 millipedes that possess an astounding number of legs, including one
 individual with 750. Due to their cryptic lifestyle, rarity in natural
 history collections, and sporadic study over the last century, the family
 has an unclear phylogenetic placement, and intrafamilial relationships
 remain unknown. Here we report the discovery of a second species of
 Illacme, a millipede genus notable for possessing the greatest number of
 legs of any known animal on the planet. Illacme tobini sp. n. is described
 from a single male collected in a cave in Sequoia National Park,
 California, USA. After 90 years since the description of Illacme, the
 species represents a second of the genus in California. Siphonorhinidae
 now includes Illacme Cook & Loomis, 1928 (two species, USA),
 Kleruchus Attems, 1938 (one species, Vietnam), Nematozonium Verhoeff, 1939
 (one species, South Africa) and Siphonorhinus Pocock, 1894 (eight species,
 India, Indonesia, Madagascar, Vietnam).
description: Dorsal view of head,
 antennae and rings 1 – 5 of I. tobini n. sp. (Fig. 2A)Scanning electron
 micrograph taken of palladium/platinum coated structures with an FEI
 Quanta 600 FEG environmental scanning electron
 microscope.2A_355x
 33tilt.tifLateral (right) view of
 head and rings 1 – 5 of I. tobini n. sp. (Figs 2C, 5E)Scanning electron
 micrograph taken of palladium/platinum coated structures with an FEI
 Quanta 600 FEG environmental scanning electron
 microscope.2C_5E_339x-2 46.5
 tilt_002.tifAnterolateral (right)
 view of head and first leg pair of I. tobini n. sp. (Fig.
 2E)Scanning electron
 micrograph taken of palladium/platinum coated structures with an FEI
 Quanta 600 FEG environmental scanning electron
 microscope.2E_34 tilt
 623x.tifLateral (left) view of
 head and first leg pair of I. tobini n. sp., antennae broken off at base
 (Fig. 2F)Scanning electron
 micrograph taken of palladium/platinum coated structures with an FEI
 Quanta 600 FEG environmental scanning electron
 microscope.2F_15E_733x 46.5
 tilt_003.tifLateral (right) view of
 antenna of I. tobini n. sp. (Fig. 3A)Scanning electron
 micrograph taken of palladium/platinum coated structures with an FEI
 Quanta 600 FEG environmental scanning electron
 microscope.3A_618x.tifVentral view of head and rings 1 – 5 of I. tobini n. sp. (Fig. 3C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.3C_270x 46.5 tilt.tifVentral view of head and rings 1 – 3 (leg pairs 2 – 6 broken off at prefemur-femur joint) (Fig. 3D)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.3D_34 tilt 540x.tifVentral view of rings 6 and 7 with sternites, pleurites and leg bases of I. tobini n. sp. (Figs 3E, 17F)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.3E_17F_251x.tifAnterior view of ring 6 sterna of I. tobini n. sp. (Figs 4A, 18A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.4A_18A_33tilt 258x.tifLateral (right) view of gonopods (leg pairs 9 and 10) of I. tobini n. sp. (Fig. 4C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.4C_36tilt 1411x.tifVentral view of gonopods of I. tobini n. sp. (centered on right posterior gonopod, leg-pair 10) (Fig. 4E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.4E_1613x.tifLateral (right) view of gonopods of I. tobini n. sp. (centered on right posterior gonopod) (Figs 5A, C; 11C; 19C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.5A_5C_11C_19C_36tilt 1420x.tifDorsolateral (left) view of tenth prozonite and metatergite of I. tobini n. sp. (Fig. 6A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.6A_324x.tifDorsal view of anterior region of head and labrum of I. tobini n. sp. (Fig. 6C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope. (Image combined with 6C_7648x-2 33tilt.tif)6C_7648x 33tilt.tifDorsal view of anterior region of head and labrum of I. tobini n. sp. (Fig. 6C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope. (Image combined with 6C_7648x 33tilt.tif)6C_7648x-2 33tilt.tifAnterolateral (left) view of head and first leg pair of I. tobini (Fig. 6E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.6E_2007x 46.5 tilt.tifAnterior view of head with gnathochilarium open showing flabellate mandibles of I. tobini n. sp. (Fig. 6F)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.6F_1739x 46.5 tilt_007.tifAnterior view of head with gnathochilarium open showing flabellate mandibles of I. tobini n. sp. (Fig. 7A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7A_2648x 46.5 tilt_009.tifAnterolateral (right) view of head of I. tobini n. sp. with gnathochilarium open showing mandibles and pectinate lamella with numerous rows of jagged ventrally projecting serrulae (Fig. 7B)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7B_34 tilt 4982x.tifDorsal view of V-shaped endochilarial frontal body of I. tobini n. sp. with fringed lobes (spatulae) protruding through gnathochilarial stipes (Fig. 7C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7C_4767x.tifAnterolateral (right) view of open mouth and keel-shaped pectinate lamella of the mandible of I. tobini n. sp. nested in V-shaped groove of the endochilarium (Fig. 7D)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7D_34 tilt 2962x.tifDorsal view of labrum of I. tobini n. sp. with deep medial incision (Fig. 7E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7E_7087x-2 33tilt.tifAnterior view of labrum of I. tobini n. sp. with heavily porous surface (Fig. 7F)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.7F_6181x.tifDorsal view of anterior region of head and labrum of I. tobini n. sp. (Fig. 8A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.8A_1921x 33tilt_001.tifVentrolateral (right) view of gonopods of I. tobini n. sp. (Figs 8C, 17E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.8C_17E_36tilt 289x-2_001.tifAnteroventral view of gonopods of I. tobini n. sp. (Figs 8E, 18E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.8E_18E_33tilt 1523x_001.tifVentral view of gonopods of I. tobini n. sp. (Figs 9A, E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.9A_9E_1398x_003.tifLateral (right) view of right anterior gonopod (leg-pair 9) of I. tobini n. sp. (Fig. 9C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.9C_36tilt 2006x_005.tifDorsal view of trunk of I. tobini n. sp. (Figs 10A, 16A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.10A_16A_363x_004.tifDorsal view of left ozopore of I. tobini n. sp. (Fig. 10C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.10C_1261x_007.tifDorsal view of metazonite posterior margin (limbus) of I. tobini n. sp. (Fig. 10E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.10E_2581x_005.tifVentrolateral view of apodous ring, telson, hypoproct and paraprocts of I. tobini n. sp. (Fig. 11A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.11A_46tilt 348x_001.tifAnterolateral (left) view of gnathochilarial stipes and dorsal surface of endochilarium of I. tobini n. sp. (Fig. 14A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.14A_6871x 46.5 tilt_005.tifAnterior view of gnathochilarium of I. tobini n. sp. with inner and outer palps (inner, outer palps with 3, 2 setae respectively) (Fig. 14B)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.14B.tifAnterolateral (right) view of open mouth and keel-shaped pectinate lamella of the mandible of I. tobini n. sp. (Fig. 14C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.14C.tifAnterolateral (right) view of mandible of I. tobini n. sp. with base of external teeth a circular socket (Fig. 14D)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.14D_34 tilt 4982x.tifAntennomere 7 of I. tobini n. sp. (Fig. 15A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.15A_2079x_001.tifDorsolateral (left) view of rings 10 – 14 of I. tobini n. sp. (Fig. 15E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.15E_259x.tifVentrolateral (right) view of posterior rings of I. tobini n. sp. (Figs 15F, 17A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.15F_17A_46tilt 133x.tifLateral (right) view of right ozopore from ring 106 (Fig. 16C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.16C_46tilt 3668x_002.tifDorsal view of trunk (Fig. 16D)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.16D_152x_003.tifOzopore of I. tobini n. sp. (Fig. 16E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.16E_5720x_008.tifVentral view of left postgonopodal legs and eversible sacs of I. tobini n. sp. (Fig. 17C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.17C_605x_001.tifVentrolateral (right) view of second leg pair of I. tobini n. sp. with posteriorly oriented coxal gonapophyses (legs broken off at prefemur-femur joint) (Fig. 18B)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.18B_34 tilt 1615x 2d legs.tifMedial view of right anterior gonopod of I. tobini n. sp. (Fig. 18C)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.18C_2307x_007.tifAnteroventral view of gonopods of I. tobini n. sp. in situ, close-up of right anterior gonopod (Fig. 18F)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.18F_33tilt 2646x_002.tifAnteroventral view of left gonopod of I. tobini n. sp. in situ (Fig. 19A)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.19A_33tilt 2810x_004.tifVentrolateral (right) view of gonopods of I. tobini n. sp. in situ (leg pairs 7, 8, 11 broken off at prefemur-femur joint) (Fig. 19B)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.19B_36tilt 995x_002.tifAnterodorsal view of head of I. tobini n. sp. with mouth open showing dorsal surface of left gnathochilarial stipe with unidentified brush-like structure (Fig. 19E)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.19E_34 tilt 4982x.tifVentral view of posterior rings of I. tobini n. sp. (Fig. 19F)Scanning electron micrograph taken of palladium/platinum coated structures with an FEI Quanta 600 FEG environmental scanning electron microscope.19F_125x.tif