Heiten near Suigen, Keiki-do, two semi-mature specimens, August, '35.
Description:
External characteristics:
Length 40 and 54 mm, greatest diameter up to 2.5 mm, number of segments 154 and 138. Dorsal pores absent, but mid dorsal line appears slightly thinner than the rest. Prostomium
prolobous. Colour in formalin, yellowish grey on both dorsal and ventral surfaces; clitellar coloration begins to appear, pinkish. Clitellar glandulation also begins to
appear, in X-XIII; its glandularity extends ventrolateralwards, and is distinct around secondary male pores, but midventrad rather non-gulandulated.
Setae short; those on II and clitellar segments not delicate, but may be a very little smaller than the rest. Behind clitellum they are slightly larger than the anteclitellar.
Anteriorly to about V aa larger than bc, but behind this region aa nearly equal to bc; ab nearly equal to cd; dd nearly equal to, or slightly smaller than, 1/2 of the circumference.
Nephridiopores, minute, in line with c; some of them may be displaced dorsalwards.
Secondary male pores (Fig 4a), one pair, each represented as a relatively very large, transverse slit in intersegmental furrow of 10/11, formed by both posterior and anterior ends of X and
XI. Medially it reaches to about a-line and laterally to near c-line. In one specimen from this slit a moderately sized, blade-shaped penis which is never pointed distally extends
out anteromedially, as large as about 0.8 mm long and 0.3 mm wide at base when fully extended. Ventral epidermis of both X and XI around secondary male pores are thickened and gently
elevated, the clitellar glandularity extending into there, but the midventral portion in this region is rather concave; setal zones of XII and XIII are also elevated though much faintly.
Female pores, one pair, invisible in these specimens externally, in line with b, in 11/12.
Spermathecal pores, one pair in 7/8, in line with c or just medial to c.
Genital papillae absent in both specimens.
Internal anatomy:
Septa 5/6 and 6/7 very much, 7/8 and 8/9 much thickened, the rest thin or delicate. Dorsal parts of 10/11 displaced posteriorly to mert dorsolaterally with 11/12 in intersegmental
space of 11/12. The other septa almost normally inserted.
Gizzards, three in one specimen in XIII-XV, and four in the other in XII-XV; spherical in shape, strong, large relatively to the body size, and rather clearly constricted from one another
to be moniform as a whole.
Last hearts in IX.
Testis sacs, one pair, small but rather massive, yellowish, each suspended by 9/10 a little larger part lying in X, faintly constricted at its lateral side by the septum. Sperm-duct
very short and very fine, shorter than the length of prostate, wholly lying behind 9/10 and making there only a few twists within a sheet of connective tissue which is apparently derived from
the ventral parietal wall, and stands in coelom to reach about to the proximal portion of the sperm-duct, and falling ventrally to the floor of the coelom in X where it penetrates into the
parities and passes laterally and then emerges into the coelom and at once may possibly enter into the entail end of the prostate. Unfortunately, in spite of my careful dissection the
position where the sperm-duct enters into the prostate was not decidedly determined; but from their relative situation the above description was written. Prostate (Fig. 4b), small,
short but relatively broad, highly warty on surface, rather flattened dorsoventrally and a brownish tubular body visible within it under the microscope, ectally slightly curved anteriorwards
and covering a part of dorsal surface of a large gland which is placed medially, entally not erected into coelom, but bent ventralwards and bound but not firmly, by a few muscle fibres to the
ventral parietal wall in anterior part of X. Duct thin and very short, concealed by a small mass of tissue, so it appears that the prostate gland directly continues to the proximal
end of the penis. Medially to the prostate is found a very large, firmly formed, glassy shining, ovoidal gland which is large as about 1/4-1/3 of the prostate, dorsally rounded and
markedly projecting into the coelom but slightly concealed by the ectal part of the prostate, ventrally with the narrowed portion passing into the penis. Penis not so long,
dorsoventrally flattened, hook-shaped, being anteromedially curved, distally never pointed. (Corresponding to the gland genital papilla was not found externally, but it may be found.)
Ovarian chamber in XI, formed by septa 10/11 and 11/12, ventrally separated by about one segment and dorsolaterally both septa fused in intersegmental space of 11/12, also around oesophagus
forming an inverted U-shape. Ovisac long, slender, extending posteriorly into XVI in the shortest case or into XXII in the longest case, its anterior portion constricted by each septum,
moniliform, empty and whitish in these specimens; thin wall of these sacs provided with much minute papilla-like swellings on its various parts... perhaps they may disappear when sacs are
filled with ripen ova as in the case of Dr. gisti. Ovaries large, much tufted.
Spermathecae, one pair, with its atrium wholly lying upon the posterior surface of 7/8. Ampulla large relatively to the body size, spherical; duct thin, moderate in length, not
sharply marked off from the former, making a small mass of coils at its ental portion, ectalwards gradually increasing its thickness in a very small degree and loosely twisted there, finally
entering into about ectal third of the atrium. Atrium somewhat sac-like, nearly equal to, or a little longer than, diameter of the ampulla, placed laterally to ampulla being erected
into coelom, its entail free portion rather rounded and slightly thicker than the rest. Just laterally to atrium is found a small, whitish, stick, and ball-like gland (Fig 4c).
Remarks:
The present species in some characters closely resembles Dr. syringa Chen (’33) and also Dr. cheni Gates; for instance, in the former species in the highly warty and small
prostate, prolonged slender ovisacs, and absent of genital papillae, and in the latter species in some characters of the male organs. But, it differs from the former mainly in shape of
penis and probably also in the structure of the other parts of the male organs, and in position where the sperm-duct enters into the atrium. The description of Dr. syringa is
rather brief, so the differences and at the same time the resemblance between them cannot be clearly shown here. But the differences above mentioned may be sufficient to supecifically
distinguish them from each other. From the latter species it is clearly distinguishable in many important characters.
日本産ミミズ大図鑑
