7_a._ _Dichelaspis pellucida_, basal end of carina of, much magnified.
8. _Dichelaspis Lowei_, (magnified nearly ten times.)
8_a._ _Dichelaspis Lowei_, fork of carina of, viewed internally.
9. _Dichelaspis Grayii_, (magnified eight or nine times.)
10. _Dichelaspis orthogonia_, (magnified six times.)
10_a._ _Dichelaspis orthogonia_, carina, lateral view of.
10_b._ _Dichelaspis orthogonia_, basal end of carina, viewed internally, much magnified.
TAB. III.
Fig.
1. _Oxynaspis celata_, (magnified three times.)
1_a"._ _Oxynaspis celata_, with the skin of the encrusting h.o.r.n.y zoophyte removed. (_a_), scutum; (_b_), tergum; and (_c_), carina.
2. _Conchoderma virgata_ (magnified twice.)
2_a._ _Conchoderma virgata_ carina, viewed externally.
2_b._ _Conchoderma virgata_ summit of capitulum, showing the terga from vertically above.
2_c._ _Conchoderma virgata_ var. _chelonophila_, (magnified four times).
2_d._ _Conchoderma virgata_ var. _Olfersii_, (scutum.)
3. _Conchoderma Hunteri_, (magnified five times.)
4. _Conchoderma aurita_, (nat. size,) with the rudimentary carina exhibited on the right hand.
4_a._ _Conchoderma aurita_, summit of capitulum, viewed from vertically above, showing the ear-like appendages and the rudimentary terga.
4_b._ _Conchoderma aurita_, section near the bases of the ear-like appendages, showing their folds.
4_c._ _Conchoderma aurita_, (var.), scutum.
5. _Alepas minuta_, (magnified five times.)
6. _Alepas cornuta_, (magnified five times.)
TAB. IV.
Fig.
1. _Anelasma squalicola_, (copied from Loven.) The ovigerous lamellae are seen within the edges of the aperture of the capitulum. Enlarged about one and a half times.
2. _Anelasma squalicola_, (from Loven), with the membranes removed from one side of the capitulum and of the peduncle, exhibiting the body.
(_a._) External membrane of the capitulum.
(_a, a._) Inner membrane of ditto, lining the sack, and separated from the external membrane by a double fold of corium.
(_b._) The ovigerous lamellae, the edge projecting beyond the orifice of the capitulum.
(_c._) p.e.n.i.s, succeeded by six pairs of rudimentary cirri.
(_d._) Probosciformed mouth.
(_e._) Orifice of the acoustic (?) sack.
(_f._) Ovigerous fraenum.
(_g._) Ovarian branching tubes filling up the peduncle.
(_h._) Outer integument of peduncle, lined by corium and muscles, continuous with the outer membrane (_a_) of the capitulum.
3. _Anelasma squalicola_, Small portion of the outer integument of the peduncle, greatly magnified, exhibiting the natural lines of splitting, and showing that it is composed of several distinct portions or layers, which are displayed by the corners having been turned over. Three of the branching filaments, filled with pulpy corium, are given; the others have been cut off. The membrane (_a_) extends under (_b_), but not under the circular patches of membrane, (_c, c_.)
4. _Anelasma squalicola._ Mandibles, seen from the side towards the maxillae.
5. _Anelasma squalicola._ Mandibles, seen from the side towards the labrum.
6. _Anelasma squalicola._ The right-hand, rudimentary cirrus, the third from the mouth.
7. _Anelasma squalicola._ Maxillae. The thin h.o.r.n.y apodeme, (_a_).
8. _Ibla c.u.mingii_, female, (magnified four times.)
8_a"._ _Ibla c.u.mingii_, female, (magnified about five times), with the right hand valves and right side of the peduncle removed. The Male (_h_) is seen attached in the sack. The peculiar form of the body, caused by the small development of the prosoma, by the distance of the first and second pairs of cirri, and by the distance of the mouth from the adductor muscle, (a dark dotted circle opposite _i_,) and lastly, the remarkable course of the oesophagus over the adductor muscle, together with the outline of the stomach, are here all exhibited.
(_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.