382 EXPLANATION OF THE PLATES. 



Fig. 



was attached to the valve now re- 

 moved, 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 seg- 

 ment of the pedicel of first cirrus. 



(e.) Orifice of the acoustic (?) sack, 

 between the bases of the first and 

 second cirrus. 



(/.) Caudal appendages. 



(p.) Branching ovarian tubes within 

 the peduncle. 



(Ji.) 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. 

 86'. Ibla Cumingii, Internal view of the scutum and ter- 

 gum, and of the upper part of the 

 outer integument of the peduncle, 

 with its horny spines magnified 

 about three times. 

 8c. „ ,, A small portion of the outer integu- 



ment of the peduncle, greatly 

 magnified, showing the horny per- 

 sistent spines ; two of the spines 

 have been torn out. 



9. Ibla quadrivalvis; internal view of scutum and ter- 

 gum, and of the upper part of 

 the outer integument of the 

 peduncle ; magnified four times. 



9a. ,, „ Penis, supported on a long un- 



articulated projection ; greatly 

 magnified. 



