Sylphella puccoon Rodriguez, Fend & Lenat 2014

(based on mated specimens). Number of segments 65–83. Length of fixed worms 15–25 mm. Diameter of the body from 14 unmounted worms in lateral aspect (measured to 0.01 mm): 0.44–0.66 mm in VIII (mean 0.51 mm), 0.45–0.68 mm at clitellum (mean 0.54 mm), and 0.50–0.76 mm (mean 0.61 mm) at mid-body. Prostomium rounded-conical, 270–400 μm long, width about the same as length. Secondary annulation (narrow ring in anterior part of segment) from segment V; present but weak in post-clitellar segments (Fig. 1A). Epidermis 10–15 μm high in anterior segments. Clitellum annular, from segment X to XIV, with epithelium up to 25–35 μm high, formed by unordered, glandular cells (Fig. 2B). Longitudinal muscles up to 32 μm thick in anterior segments. Chaetae sigmoid, simple-pointed with strongly curved distal tip; ventral chaetae larger than corresponding dorsal chaetae in anterior segments (Table 1). Ventrals largest in II to about XIII (126–204 μm long, up to 7 μm thick), anterior dorsals distinctly smaller and thinner, (60–130 μm long, 4 μm thick) (Fig. 1B); maximum ventral chaeta length about 1.6 that of dorsals in preclitellar segments. Ventral chaetae only slightly larger than dorsals in post-citellar segments. Nodulus at about 0.32–0.46 (mean = 0.40) from the distal end. Length (μm) of chaetae in Sylphella puccoon gen. n., sp. n. (measurements on one whole-mounted specimen from Pokeberry Cr., North Carolina, USA 14 Jan 2009). Segment II III IV V VI VII VIII IX X Posterior Dorsal 63 – 88 90 103 94 118 120 120 99–121 Ventral 167 141 140 141 162 154 140 141 132 95–124 Ventral/dorsal length 2.6 – 1.6 1.6 1.6 1.6 1.2 1.2 1.1 1.0 Transverse, oval male pores are in line of ventral chaetae of segment X and XI, about midway between chaetae and posterior septum (Fig. 1A). Female pores open just below the lateral line, in intersegment 12/13. Inconspicuous, round spermathecal pores open behind, and in line with the ventral chaetae in XII–XIII. Pharynx developed mainly dorsally and laterally, in segments II and III. Pharyngeal glands well developed dorsally and ventrally in IV–VI, usually extending ventrally into VII. Chloragogenous tissue well developed from VII backwards. A supra-intestinal vessel may appear differentiated from the perivisceral sinus (Fig. 2E) beginning in XIV; this is not evident after the dorsal vessel joins the gut in about XX. One pair of simple commissural blood vessels join dorsal and ventral vessels in anterior segments to about XV; those in XII may loop into the egg sacs (Fig. 2D). Lateral blood vessels absent from posterior segments except for 1–2 very short lobes on dorsal vessel in about the posterior 1/4 of the body (Fig. 1E). Nephridia usually paired in VII and VIII, and paired, single, or absent in segments posterior to XIII; efferent ducts simple, mostly limited to ventral half of body, without vesicles at nephridiopores. Sperm sacs extend anteriorly to VIII or IX, and backwards as far as XXII. Egg sacs may extend to 2 or 3 segments beyond sperm sac; when eggs have partially completed vitellogenesis, egg sacs shorter, not extending beyond sperm sacs, to XIII or XIV. Two pairs small testes, in segments X and XI; one pair elongate ovaries in XII, extending through XIII. Female funnels large, attached to the septum and opening in intersegment 12/13. Two pairs spermathecae, the first in the post-atrial segment (typically XII), and the second in the post-ovarian segment (typically XIII) (Figs 1C, 2F). A single vas deferens per atrium (prosoporous condition), sperm funnels located on the septa of intersegments 10/11 and 11/12 (posterior septa of atrial segments), but folded back into the next segment. Vasa deferentia long (about 700 μm), penetrating the posterior septa, and forming a long, convoluted loop within each post-atrial segment (Fig. 1C). Vasa deferentia narrow (12–16 μm diameter) and transparent, each joining the atrium at the ectal (or basal) part of the ampulla (adjacent to the atrial duct), and running under the atrial musculature to about the middle part of the ampulla, where it opens into the atrial lumen (Fig. 1C, D). Atria petiolate, extending medially from male pore, with nearly spherical ampulla (140–210 μm diameter, slightly longer than wide) and tubular ectal duct (Fig. 1D). Ampullar musculature very thick (40–50 μm), organized in many intercrossing layers (Fig. 2H–J). Atrial ampulla with very thin epithelium, and covered by a thin (up to 5 μm) layer of cells and prostate glands formed by elongate-petiolate clusters of cells; each gland is pedunculate with a narrow extension penetrating the atrial musculature (Fig. 2I). Atrial duct tubular (17–24 μm diameter, 90–110 μm long), composed of an epithelium surrounded by loose, indistinct musculature, extending into a type-1 penis (Fig. 17, in Rodriguez and Giani 1994) within a deep penial sac (120–230 μm deep) (Figs 1C, D, 2M), and associated with retractor muscles extending dorso-laterally to the body wall. Penis length 90–110 μm; the broad, ental part forms a distinct epithelial tube which disappears ectally; the middle portion is surrounded by a ring of what appears to be circular musculature; and the ectal part is sharply acuminate, covered by a thin (ca.1 μm), cuticular layer. The spermathecae have a narrow duct and an irregular, sacciform ampulla. Spermathecal duct fusiform, (30–45 μm maximum diameter), formed by columnar epithelium, a thin (about 2 μm) muscle layer, and with a wide lumen except at the pore; ental end of the duct prolonged into a narrow neck (12–20 μm diameter) which joins the ampulla (Figs 1C, 2L). Duct sharply narrowed at the pore, with a short sphincter surrounded by a circular muscle layer (Figs 1C, 2K). Ampulla in two parts, a short ectal section (60–90 μm long by 35–46 μm wide), lined with irregular epithelium, and a much larger ental part (320–480 μm by 130–250 µm), which is lined by columnar, vacuolated epithelium, up to 35 μm thick (Fig. 2G, K). Sperm within the spermathecae loose and unordered; epithelial vacuoles not obviously containing resorbed sperm. All spermathecae similar in size; ampullae of mated worms may extend into adjacent segments.