Indiella ridgenensis Sautya, Tabachnick & Ingole 2011

Body: The sponge consists of small, lamellate, thin fragments. The holotype is a flat fragment approximately 40?17 mm about 1 mm in thickness (Fig. 2i). Paratypes are similar: Pi is a lamellum 20?25 mm (Fig. 2ii); Pii is 30?20 mm (Fig. 2iii); Piii is 50?45 mm (Fig. 2iv). From the dermal side numerous epirhyses are observed, they are 1.3 – 1.5 mm (Fig. 4C) in diameter and penetrate about a half of the wall thickness. Spicules framework is seems to be constructed of different elements: regular, longitudinally directed dictyonal strands, located mostly in the vicinity of the atrial surface (approximately 4 layers) and irregular hexactins fused to each other and to the regular elements at points of mutual contacts, at all levels of the wall thickness. All framework surfaces are covered by very small spines, the free outer ray ends are conically pointed. The dictyonal strands are easily observed, they have diameter 0.09–0.12 mm, beams between the strands are 0.03–0.07 mm in diameter. Free rays of the dictyonal strands are protruded atrially. The meshes between the dictyonal strands and their connecting beams are rather regular, usually rectangular, 0.3–0.5?0.5–0.8 mm. Adjacent hexactinic spicules located among the dictyonal strands are irregularly and sparsely distributed among their meshes, they are connected to the framework by a single ray (small hexactins with rays 0.07–0.12/0.003–0.006 mm) and often at points of mutual contact (large hexactins with rays about 0.5/0.012–0.018 mm). The meshes there are very irregular and of different sizes. The dictyonal strands may be also observed in the vicinity of dermal surface but due to numerous epirhyzes, they are not straight as those from the atrial surface. Loose spicules: dermal and atrial pentactins are similar to each other, they always have a rudiment about 0.02 mm long instead of the ray directed outside the body, rough surface, their outer ends are clavate, rounded, lanceolate or sometimes conically pointed. Tangential rays of dermal pentactins are 0.102–0.432 mm long (Table 1), the ray directed inside the body is 0.048–0.258 mm long (Table 1), the diameter of these rays is 0.002–0.009 mm. Tangential rays of atrial pentactins are 0.078–0.372 mm long, ray directed inside the body is 0.036–0.342 mm long (Table 1), the diameter of these rays is 0.004–0.009 mm. Microscleres are stellate discohexasters only, with 8–14 secondary rays. The diameter of the discohexaster is 0.025–0.046 mm, their primary rosette is 0.006–0.018 mm in diameter (Table 1). Spicule dimensions of Indiella gen. n. ridgenensis sp. n. (in mm). L - length, D - diameter, d - diameter of a primary rosette (N = number of observations; Min = minimum; Max = maximum; Avg = average; SD = standard diviations). Bold measurements are used in the text sections. Type L Dermal pentactin L Atrial pentactin Discohexaster Tangential ray Ray directed inside body Tangential ray Ray directed inside body D discohexaster d discohexaster Holotype N 25.000 25.000 25.000 25.000 28.000 28.000 Min 0.102 0.060 0.078 0.042 0.025 0.006 Max 0.432 0.258 0.360 0.342 0.046 0.018 Avg 0.280 0.103 0.228 0.100 0.039 0.012 SD 0.099 0.048 0.081 0.067 0.005 0.003 Paratype-1 N 16.000 16.000 12.000 12.000 14.000 14.000 Min 0.168 0.048 0.108 0.060 0.032 0.009 Max 0.408 0.180 0.360 0.156 0.042 0.018 Avg 0.256 0.113 0.264 0.115 0.037 0.012 SD 0.070 0.049 0.076 0.032 0.003 0.002 Paratype-2 N 7.000 7.000 6.000 6.000 3.000 3.000 Min 0.240 0.078 0.132 0.048 0.039 0.012 Max 0.414 0.192 0.372 0.114 0.041 0.014 Avg 0.348 0.127 0.241 0.075 0.040 0.013 SD 0.060 0.039 0.095 0.023 0.001 0.001 Paratype-3 N 5.000 5.000 4.000 4.000 1.000 1.000 Min 0.168 0.072 0.150 0.036 0.032 0.008 Max 0.312 0.168 0.240 0.084 0.032 0.008 Avg 0.252 0.110 0.197 0.066 0.032 0.008 SD 0.067 0.037 0.038 0.021 - -