266 W. Lilljeborg on the Genera Peltogaster and Liriope. 



per collum connexa. Nulli oculi, nulli pedes, nulleeque appendices 

 branchiales. Pullus et sine dubio mas iisdem Bopyri admodum 

 similes, et fere tantummodo pedibus tboracicis postremi paris, 

 ungue longo et recto neque retractili armatis, diversi. 



EXPLANATION OF PLATE IV. 



Fig. 1. a. Liriope pygmcea, female, containing eggs and young, attached 

 to the Peltogaster Paguri, b, which is fixed in its turn to Pagurus 

 pubescens, Kroyer ; all seen from above. 



Fig. 2. Liriope pygmcea, female, dead and preserved in spirit, seen from 

 above : a, anterior extremity of the body, or cephalothorax ; 

 by posterior part of the body, or matrix ; c, the right, d, the left 

 side. 



Fig. 3. Liriope pygmcea, female, alive, seen from beneath : a, anterior 

 extremity ; b, posterior part with the supposed anal aperture, and 

 the fissure of the matrix between this aperture and the anterior 

 part of the body (cephalothorax). On the cephalothorax the 

 mouth is seen as a black point. 



Fig. 4. The larva of Liriope seen from above: a a, anterior antennae, or 

 first pair ; b b, posterior antennae, or second pair ; c c, five anterior 

 pairs of thoracic feet ; d d, sixth or last pair of thoracic feet ; 

 e e, five anterior pairs of abdominal feet ; //, last pair of abdo- 

 minal feet, or caudal feet. 



Fig. 5. The same, seen from the left side. 



Fig. 6. Pachybdella Carcini, seen in front (after Loven) : a, acetabulum ; 



b, orifice of the pallium. 



Fig. 7. The same, opened: a, acetabulum; b, orifice of the pallium; 



c, the fleshy body ; d d, the ramified external ovaries (ovarian 

 caeca). 



Fig. 8. The organ of adhesion of Peltogaster Paguri, seen from beneath : 

 a, the orifice of the mouth ; b, the buckler, to which the aceta- 

 bulum is attached by its neck beneath the Peltogaster. In this 

 buckler concentric striae of cement are seen ; and attached to the 

 margins of the acetabulum are fragments of the epidermis of the 

 Pagurus to which the Peltogaster was attached. 



Fig. 9. The two primary ovaries of P. Paguri surrounded by a cellular 

 membrane and different formative matters. 



Fig. 10. Peltogaster sulcatus, filled with eggs and deprived of its pallium. 

 The two sacs of eggs are completely united and surrounded by 

 the delicate membrane which clothes the cavity of the body, and 

 which adheres by a cellular tissue to the inner surface of the 

 pallium or skin. This membrane is produced at b, over the 

 inner surface of the short tube which surrounds the anterior 

 orifice ; a a, the two parts supposed to be male generative organs, 

 probably vesiculce seminales. 



Fig. 11. One of the seminal vesicles magnified. 



Fig. 12. Peltogaster Paguri, filled with eggs, seen from above (length 

 13millim.): a, acetabulum; b, anterior aperture of the body; 

 c, posterior extremity of the body, with a fissure and internal 

 line of demarcation between the two sacs of eggs, which is con- 

 tinued towards the anterior extremity. 



Fig. 13. The same, deprived of the organ of adhesion, seen from beneath 

 (length 9 millim.) : a, the anterior orifice of the body; b, the 

 posterior extremity, with the boundary between the two sacs of 

 eggs. 



