Tidesmus episcopus Chamberlin, 1943

Shear, William A. & Shelley, Rowland M., 2007, The milliped genus Tidesmus Chamberlin, 1943 (Polydesmida: Macrosternodesmidae), Zootaxa 1656, pp. 51-68 : 56-58

Tidesmus episcopus Chamberlin, 1943

Figs. 1–4

Tidesmus episcopus Chamberlin, 1943:35 , figs. 1–3; 1952:558. Chamberlin and Hoffman, 1958:74. Buckett, 1964:12. Shelley, 2002b:107.

Phreatodesmus cooki Loomis, 1960:64 , fig. 12. Buckett, 1964:12. Hoffman, 1999:470. Shelley, 2002b:107. NEW SYN- ONYMY.

Type specimens: Of T. episcopus , male lectotype and male and female paralectotypes ( FMNH) collected by G. Grant, 2 January 1939, on Bishop's Road, Reservoir Hill, Los Angeles, Los Angeles Co., California. Today, Bishops Road is a one or two block street bordering Elysian Park between the Pasadena Freeway and North Broadway St., near Dodger Stadium. The vial containing the types and only known specimens is labeled “male holotype, female allotype,” but it contains fragments of at least three males and two females, with one male segregated in a microvial. Chamberlin (1943) did not designate a holotype nor did he designate a lectotype in his subsequent report of this sample ( Chamberlin 1952), so the specimens are thus syntypes. His handwriting is on the label, so we designate the male in the microvial, the least damaged specimen, as the lectotype; the others thus become paralectotypes. Parts of one male paralectotype were mounted for examination by scanning electron microscopy. Of P. c o o k i, male holotype & 11 juv. paratypes ( USNM) collected by O.F. Cook, 15 February 1929, along Clear Creek, Tehachapi Pass, Kern Co., California.

Diagnosis. Process B a simple, curved projection overhanging ventrolateral margin of acropodite, without basal branch or other substructures; acropodite without true distal zone, margin irregularly folded with short spiniform projection and elevated, transverse lamella.

FIGS. 1, 2. Tidesmus episcopus gonopods. 1, in situ, ventral view. 2, terminal structures, mesial view.

Description. Length ca. 9–9.5 mm, maximum width ca. 0.85 mm; somatic features agreeing with those of T. variabilis (detailed description in succeeding account). Gonopodal aperture (Fig. 1) large, broadly ovoid, completely filling 7th metazonite, not extending anteriad onto prozonum or caudad between 9th legs, sides slightly elevated. Gonopods in situ (Fig. 1) completely filling respective halves of aperture, prefemora contiguous in midline. Gonopod structure as follows (Figs. 1–4): Coxa (cx, Fig. 1) large, globose, tapering into blunt, anterolateral projection; telopodites comparatively small, arising caudomediad from coxae. Prefemur (pf, Fig. 1) rounded basally at insertion of cannula, angling anteroventrad distad, not horizontal, process B (b, Figs. 1,2) arising distad on anterolateral margin, with broad, subtriangular basal lobe (best seen in Fig. 3 ), projection extending laterad basally then curving broadly ventromediad, overhanging and terminating near level of distolateral acropodal margin, apically uncinate; acropodite (ac, Fig. 1) short, "blocky," and irregularly folded with a few short, spiniform projections, longest arising anterodistad at base of distal zone (dz, Fig. 2); latter a minute, inconspicuous, sublinear lamella oriented transversely across ventral acropodal surface, margin irregularly notched; solenomere (s, Fig. 2) moderately long, extending caudad then curving mediad over distal zone and ventral acropodal surface, apically uncinate.

Females with somatic features subsimilar to those of males but without swellings on ambulatory prefemora (see description of T. variabilis ).

Habitat. According to the vial label, the types of T. episcopus were found "under stones."

Distribution. A small area extending from the Tehachapi Mountains southward through the western San Gabriels to the foothills of northern metropolitan Los Angeles (Fig. 25); T. episcopus should be expected in Griffith Park and the Hollywood Hills. The two Kern Co. sites are close together and lie roughly 80 mi (128 km) north-northwest of the type locality. In addition to the types, the following locality is available: CALI- FORNIA: Kern Co., Woodford (near Tehachapi), m, 8 January 1929, O. F. Cook (VMNH).

Etymology. The specific name refers to the type locality, Bishop's Road ( Chamberlin 1943).

Remarks. Chamberlin (1952) merely repeated the type locality and the number of specimens in the sample.

The VMNH male from Kern Co. was in a jar of P. cooki labeled “ PARATYPE ” and there is a label in the vial stating such. The individual was available to Loomis (1960), but he did not designate it as a paratype in the published description and thus it does not hold this status (Article 72.4.6 of the Code).

Figures

FIGURES 3 – 8. Gonopods of Tidesmus species. 3 – 4, T. episcopus. 3, right gonopod, lateral view. 4, right gonopod telopodite, mesial view. 5 – 8, T. variabilis. 5, left gonopod, mesial view. 6, the same, lateral view. 7. left gonopod telopodite, lateral view. 8, the same, mesial view.