8. Amynthas morrisi (Beddard, 1892)

(Figures 1 F, 14)

Perichaeta morrisi Beddard, 1892a: 166 .

Pheretima morrisi — Gates 1937: 361; 1954: 238; 1958: 31; 1963: 14; 1968: 253; 1982: 60. Amynthas morrisi — Sims & Easton 1972: 236. Reynolds 1978: 127; 2010: 148; 2011: 276. Reynolds & Wetzel 2004: 88; 2008: 180. Blakemore 2014: 131.

Data sources. Gates (1937, 1968, 1972, 1982); Blakemore (2014).

Diagnosis. Size 40–150 mm by 2–6 mm. Segment numbers 75–102. Color of live specimens unknown. Male pores paired in XVIII, on small, circular porophores. Post-clitellar genital markings present or absent; when present, two immediately median to each male porophore, one pre-setal and one post-setal, one of the two sometimes absent, slightly larger than the porophore, surrounded by several concentric furrows. Additional presetal markings on XVIII and XIX in some specimens, mid-ventral or median to male pores, numbers variable. Spermathecal pores two pairs in 5/6/7. Pre-clitellar genital markings paired and/or unpaired small discs varying in numbers and positions; paired on some of VI–IX, median to spermathecal pore; unpaired on some of V–IX, midventral, pre-setal. Female pore single in XIV. First dorsal pore 10/11 or 11/12. Spermathecae two pairs in VI–VII. Prostate glands paired, extending through some or all of XVII–XXIII. Intestinal caeca paired in XXVII, simple, extending anteriorly to XIV.

Remarks. Amynthas morrisi was first recorded in the continental US in 1916 in Waxahachie, Texas (Gates 1937). Reproduction of this species is amphimictic. The identity of what have been commonly recognized as “ A. morrisi ” in Asia and North America was recently questioned by Blakemore (2014), who believes the name A. morrisi should be restricted to specimens with no genital markings around male pores. Regardless of whether the US specimens should be called A. morrisi or not, all US specimens registered as A. morrisi in the USNM collection appear to belong to a single species (C.-H. Chang, personal observation). As the type specimen of A. morrisi is missing and the original description by Beddard lacks enough details, addressing this issue is unattainable at this moment.