EXPLANATION OF THE PLATES. 381 



Fif 



1 S- 



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 

 (5), but not under the circular 

 patches of membrane, (c, c.) 



4. Anelasma squalicola. Mandibles, seen from the side 



towards the maxillae. 



5. „ „ Mandibles, seen from the side to- 



wards the labrum. 

 0. „ „ The right-hand, rudimentary cir- 



rus, the third from the mouth. 



7. „ „ Maxillae. The thin horny apo- 



deme, (a). 



8. Ibla Cumingii, female, (magnified four times.) 



8a. „ „ „ (magnified about five times), with 



the right hand valves and right 

 side of the peduncle removed. The 

 Male (A) is seen attached in the 

 sack. The peculiar form of the 

 body, caused by the small de- 

 velopment 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 clotted circle op- 

 posite i,) and lastly, the remark- 

 able 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 



