Eviulisoma ngaia, VandenSpiegel, Didier & Golovatch, Sergei I., 2014

VandenSpiegel, Didier & Golovatch, Sergei I., 2014, The millipede genus Eviulisoma Silvestri, 1910 in Kenya, with descriptions of new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 459, pp. 11-34 : 13

Taxon classification Animalia Polydesmida Paradoxosomatidae

Eviulisoma ngaia sp. n. Fig. 1, Map 1

Type material.

Holotype ♂ (MRAC 20799), Kenya, Ngaia Forest, N00°19', E38°02', ca 1070 m a.s.l., 2.XII.2002, leg. D. VandenSpiegel.

Paratypes: 3 ♂, 1 ♀, 1 juv. (MRAC 22634), 1 ♂ (ZMUM ρ 2442), same data, together with holotype; 1 ♂ (MRAC 20703), same data, 3.XII.2002, leg. D. VandenSpiegel.

Name.

To emphasize the type locality, a noun in apposition.

Diagnosis.

Differs from all congeners but Eviulisoma ngaiaorum sp. n. in the absence of a sternal excavation in ♂ segment 6, from Eviulisoma ngaiaorum sp. n. in the absence of sternal cones in the ♂ and by the presence of a well-developed, phylloid, postfemoral process of the gonopod (Fig. 1 C–E). See also Key below.

Description.

Length of holotype ca 16 (♂), of adult paratype ca 18 mm (♀), width of midbody metazonae 1.5-1.6 (♂) or 2.0 mm (♀). Coloration uniformly yellowish, often with an annulated pattern of slightly more intense yellowish to marbled reddish yellow metazonae. Legs usually slightly lighter to nearly pallid.

Body subcylindrical, metazonae only faintly vaulted laterally compared to prozonae (Fig. 1A, B). In width, collum> segment 2> head = segments 5-16> 3 = 4 (♂) or head = segments 6-16> 2 = 4 (♀); body behind segment 17 gradually tapering towards telson. Clypeolabral region rather densely setose, vertigial region bare (Fig. 1A). Antennae medium-sized, only slightly clavate, reaching behind body segment 2 (♂) or its midpoint (♀) when stretched dorsally; in length, antennomere 2 = 3 = 6> 4 = 5> 1 = 7; antennomeres 5 and 6 each with a distodorsal compact group of tiny bacilliform sensilla (as in Fig. 4G). Paraterga nearly missing, on each side a large, broadly rounded, ventrolateral lobe only in collum; a modest, caudally invariably rounded ridge demarcated by a premarginal lateral sulcus only dorsally in segment 2, thereafter totally wanting (Fig. 1A, B). Ozopores lateral, rather inconspicuous (as in Fig. 4B, C), lying at ca 1/3 of metazonite length in front of caudal margin (Fig. 1B). Body surface dull to poorly shining, smooth, microalveolate to faintly shagreened. Axial line missing. A transverse metatergal pigmented line traceable only dorsally in caudal 1/3 on segments 5-18, absent from 19th. Tergal setae short, mostly ca 1/4-1/5 as long as metazonite, largely abraded, pattern traceable only as 2+2 or 3+3 setae, but not their insertion points, placed in anterior 1/3 of metaterga. Stricture dividing pro- and metazonae rather thin, shallow, smooth. Pleurosternal carinae rather evident, arcuate ridges devoid of a caudal tooth, visible until segment 10 (♂) or 7 (♀). Epiproct (Fig. 1B) long, flattened dorsoventrally, very faintly concave apically, subapical lateral papillae small, but evident, removed unusually far forward from tip. Hypoproct nearly semi-circular, caudal 1+1 setae clearly separated, borne on minute knobs and clearly removed from caudal margin.

Sternites generally without modifications, densely setose, cross-impressions evident, but axial impressions especially weak; a subquadrate, densely setose lobe between ♂ coxae 4 (Fig. 1C), sternite between ♂ coxae 5 caudally, sterna between ♂ coxae 6 and 7 entirely and clearly flattened. Legs densely setose, rather short, with neither adenostyles nor dorsally bulged prefemora, 1.1-1.2 (♂) or 0.9-1.0 (♀) times as long as body height; ♂ tibial and tarsal brushes consisting of modified setae (as in Fig. 4 D–F), present until a few last leg-pairs, tibiae thereby being a little, but clearly shorter than tarsi; ♀ tarsi ca 1.5 times as long as tibiae (as in Fig. 4B).

Gonopods (Fig. 1 C–E) compact, with a lamellar solenophore (sph) (= tibiotarsus in Jeekel’s (2003) terminology) about as long as a flagelliform solenomere (sl), both being considerably higher than a simple, phylloid, postfemoral process (p).

Vulvae densely setose, without peculiarities, as in Fig. 4M, N.

Remarks.

Due to flattened, not deeply excavate, sterna between ♂ coxae 6 and 7, this species resembles Eoseviulisoma Brolemann, 1920, but the presence of a central lobe between ♂ coxae 4 warrants the assignment of this species to Eviulisoma . Brolemann (1920: 163) diagnosed Eoseviulisoma as follows.

"Sous-genre Eviulisoma , s. str. - Un prolongement entre les pattes de la 4e paire. Une excavation sternale accentuée au 6e segment. - Tronc du télopodite des gonopodes plus court que les rameaux. Suture transverse des métazonites lisse. - Type: E. Cavalli Silv.

Sous-genre Eoseviulisoma , nov. - Pas de prolongement entre les pattes de la 4e paire. - Excavation sternale du 6e segment très faible. - Tronc du télopodite des gonopodes plus long que les rameaux. - Suture transverse des métazonites perlée. - Type: Eviulisoma julinum Att."