トサミミズ

＜原記載（クリックして展開）＞

 

External characters:

　　Avereage; of body length 175 mm, of body width 5.5 mm at segment XVIII, and of number of segments 134.

　　The colour is dark brown on the dorsal surface, and light grey on the ventral.

　　The spermathecal openings are of four pairs in V/V, VI/VII, VII/VIII and VIII/IX.  The pores are large compared to other species of the genus, as is shown in Text-fig. 3, 1.

　　The proportion of the intersegmental circumference where the spermathecal openings are situated to the circular distance between the spermathecal openings ventrally, are as follows; Circumference 16.5-18.5 mm, circular distance between two spermathecal openings 4-4.7 mm, ratio 3.9-4.1.

　　The clitellum is well developed and occupies 3 segments, XIV, XV and XVI, intersegmental furrows lacking, but with dorsal pores and as usual there are no setae.

　　Setae beginning on segment II.

　　The average number of setae in some of the segments in three individuals are as follows; On segment V, 74 in average, on VI, 80 in average, on VII, 82 in average; on VIII, 84 in average; and on XX, 94 in average.

　　The openings of male pores in segment XVIII are situated close to the lateral border on the slightly elevated oblong area.  The apertures are transversely-slit of eye-shape, lie on the setal line as is shown in Text-fig. 3, 2, and separated by 9 or 10 setae.

　　First dorsal pore is in XII/XIII.

 

Internal characters:

　　There are 4 pairs of spermathecae in segment VI, VII, VIII and IX.  Each has a diverticulum.  The ampulla is cherry-shaped and slightly dorsoventrally flattened; about 1.8 mm long, 1.1 mm broad in widest portion, and continuous to the spermathecal duct which is about 0.7 mm in length.  The diverticulum opens in the terminal portion of the duct, is longer than the combined length of duct and ampulla, about 3 mm long, not coiled or looped, it is much swollen in the about the middle region and forms a long and transparent chamber.  In the diverticulum gland are many shining oil drop-like bubbles which can easily be seen from the outside due to the thin membrane cover; these are features of specific value.

　　Ovaries in usual position.

　　Prostate gland extends through segments XVII-XIX (about 3 segments occupied), the gland in this species are less developed and very thin compared with other species.

　　The prostatic duct subdivides into from 8 to 11 minute branching ducts, and enters into the gland.

　　The succular intestine commences in XV, with one pair of intestinal coeca in XXVII, it is a single projection as usually seen in the species with four pairs of spermathecae, and extends anteriorly to XXII.  From 4 to 6 serriformed coecum on the dorsal margin.

　　The septum V/VI and VI/VII much thickened, VII/VIII slightly thickened, VIII/IX, IX/X lacking, X/XI and XI/XII thickened, XII/XIII slightly thickened, XIII/XIV and XIV/XV thickened, XV/XVI slightly thickened.  The succeeding septa gradually thinner.

　　The seminal vesicles, in XI and XII, are large compared to other species of the genus.  It is very interesting to find that the anterior vesicle of this species are each combined at both dorsal and ventral sides and form a mortar-shape with the vesicle.  This feature is generally not seen in other species of the same genus.

　　The anterior vesicle are larger than the posterior.

 

Remarks:

　　The author believes that the prostatic duct, which subdivided into from 8 to 11 minute branching ducts in the present species, is one of its characteristics.  This character has not been seen in the Japanese Pheretima.

　　The anterior seminal vesicle of this species are each combined at its dorsal and ventral sides and form a mortar-shape with the vesicles.  This feature is generally not seen in the other species of the same genus.