(a.) Scutum; the end of the large rounded adductor muscle, which was attached to the valve now removed, near its apex, is plainly seen.

(b.) Tergum.

(c.) On a line with this letter, is seen the largely bullate labrum, forming a blunt overhanging projection.

(d.) Palpus, close to the upper segment of the pedicel of first cirrus.

(e.) Orifice of the acoustic (?) sack, between the bases of the first and second cirrus.

(f.) Caudal appendages.

(g.) Branching ovarian tubes within the peduncle.

(h.) Male, on the same scale, lying in its natural position within the sack, with the lower part of its peduncle bent upwards, and imbedded in the corium and muscles of the female.

(i.) Adductor scutorum muscle.

[8b´.] [Ibla Cumingii], Internal view of the scutum and tergum, and of the upper part of the outer integument of the peduncle, with its horny spines magnified about three times.