Marine sponges of the family Halichondriidae Gray, 1867 have an irregular choanosomal skeleton consisting of a high density of spicules arranged in confusing, vague, ill-defined,directionless tracts and spicules (Hooper et al., 1997). Finding conspicuous anatomical characteristics of the genus Halichondria has been a particular challenge for sponge taxonomists (Carvalho and Hajdu, 2001).

The genus Halichondria is characterized by a tangential ectosomal skeleton carried by subectosomal spicule tracts or brushes separated by subdermal spaces. Megascleres of the genus Halichondria have only oxeas or derivates in a wide range of sizes (de Laubenfels, 1936; Hooper and van Soest, 2002). Approximately 110 species from all regions and habitats have been recorded (Hooper and van Soest, 2002). Nine species of Halichondria from Korean waters have been reported (Kim et al., 1968; Rho and Lee, 1976; Kang and Sim, 2008a, 2008b; Jeon and Sim, 2009; Kim and Sim, 2009).

Sponges were collected from Uljin-gun, Gyeongsangbuk-do, Korea by SCUBA diving during 2007. Specimens were fixed in 95% or 99.9% ethanol. Spicules were observed under a light microscope (Carl Zeiss Axioskop II; Carl Zeiss, Jena, Germany). Identification was made on the basis of external features of sponges, growth form, skeletal structure, and spicule size and form. For observation of the endosomal skeletal structure, thin free-hand sections were made with specimens hardened in alcohol using a surgical blade. Spicules were prepared by dissolving a piece of sponge in sodium hypochlorite and examined under an scanning electron microscopy (Rutzler, 1978; Hooper, 1996). Holotypes of two new species have been deposited in the Department of Biological Sciences, Hannam University, Daejeon, Korea.

Phylum Porifera Grant, 1836

Class Demospongiae Sollas, 1885

Order Halichondrida Gray, 1867

Family Halichondriidae Gray, 1867

1*Halichondria jangseungenesis n. sp.

Kang and Sim, 2011 (Fig. 1)

[Fig. 1.] Halichondira jangseungenesis n. sp. A Entire animal; B Oscule opened at the top of the column like a chimney; C D Surficial skeletal structure; E Endosomal skeletal structure (longitudinal section); F Oxeas. Scale bars: A=2 cm B=0.2 cm CD=200 ㎛ E=400 ㎛ F=100 ㎛.

Holotype (Por. 104), Uljin-gun, Gyeongsangbuk-do, 1 Apr 2007, SCUBA 25 m depth, by Lee JR, deposited in the Department of Biological Sciences, Hannam University, Daejeon, Korea.

Encrusting with chimney. Sized up to 4×3 cm wide and 0.2 cm thick. Oscules, 0.2-0.5 cm in diameter, opened at top of chimney. Osuclar chimney, characteristically grooved. Colour orange in life and gradually changed to ivory in alcohol. Texture Firm and compressible. Surface smooth. Ectosomal skeleton tangential arrangement and intercrossing bundles of spicule. Choanosomal skeleton composed of many spicular tracts and individual spicules scatter-

[Fig. 2.] Halichondria nagokenesis n. sp. A Entire animal; B Spicules (oxeas); C Surficial skeletal structure; D Skeletal structure (longitudinal section). Scale bars: A=1 cm; B C=300 ㎛; D=500 ㎛.

ed whole body in confusion. Spicules composed of one type of oxea without microscleres. Oxea approximately 215-290×5-7.5 ㎛ in size.

The species is named after the type locality, Janseungbaegi, Uljin-gun, Korea.

Halichondria jangseungenesis n. sp. is similar to H. panicea (Pallas, 1766) in type of spicule and choansomal skeletal structure; however the former differs from the latter in size of spicule. The oxea of spicules is smaller than that of H. panicea. The shape of H. surrubicunda Hoshino, 1981, and H. corrugate, Diaz et al., 1993, were described as an irregular encrusting form with or without exhallent hollow cylinder/massive-lobate with oscular chimneys, and the composition of spicules with one type of oxea; thus, H. jangseungenesis n. sp. is close to these two species in these aspects. Nevertheless, they differ from this new species in their size of oxea, 300-500 ㎛, while in this new species 250 ㎛.

1*Halichondria nagokenesis n. sp.

Kang and Sim, 2011 (Fig. 2)

Holotype (Por. 105), Uljin-gun, Gyeongsangbuk-do, Korea, 1 Aug 2007, SCUBA 20 m depth, by Lee JR, deposited in the Department of Biological Sciences, Hannam University, Daejeon, Korea.

Thick encrusting with numerous erect hollow cylindrical tube, 2.5-5 cm high. Sized up to 8×5 cm wide and 1.5 cm thick. Oscules, 0.3-0.5 cm in diameter, opened at top of each tube. Color ivory in ethyl alcohol. Texture soft. Surface smooth. Ectosomal skeleton tangential arrangement. Choanosomal skeleton large and extensive subchoanosomal space present, irregular and large-meshed net of spicuels, columns with spicules extend to surface and supporting ectosomal skeleton. Spicules composed of one type of oxea without microscleres.

Oxea approximately 500-670×10-15 ㎛ in size.

The species is named after the type locality, Nagok, Uljin-gun, Korea.

H. nagokenesis n. sp. resemble H. cylindrata Tanita and Hoshino, 1989, in their growth form, with a welldeveloped hollow cylinder. Also, oscules open at the top of each tube. However, oxea of the new species is larger than that of H. cylindrata. The length of oxeas in the new species, 500-670 ㎛, is nearly double that of the H. cylindrata, 230-315 ㎛. This new species is similar to H. osculum Lundbeck, 1902, in its growth form, spicule composition and skeletal structure. However, oxea of H. nagokenesis n. sp., 500-670㎛ in length, is smaller than that of H. osculum 600-920㎛ in length.

Korean name: 1*장승해변해면(신칭)       Korean name: 1*나곡해변해면