W. Lilljeborg on the Genera Liriope and Peltogaster. 51 



meter ; their walls are formed of irregular cells. The gland was 

 empty in one specimen, its contents having probably been dis- 

 charged when the ova quitted the internal ovaries ; in another 

 the gland was filled with a cellular matter, and the walls were 

 composed, as described by Leuckart, of cylindi'ical cells. Leuckart 

 regards this as a cement-gland ; and the corneous tubercles found 

 in its vicinity render this view not improbable. Otherwise, if 

 the two sacciform organs are not testes, this gland may be sup- 

 posed to be a testis, as it presents some resemblance to the testes 

 of the Cirripedia. 



Clistosaccus * Paguri, nov. gen. et spec. 



This parasite was found, in July 1859, upon two small speci- 

 mens of Pagurus Bernhardus, taken at Christinebourg, in 

 Bohuslaen. There was a single specimen on each Pagurus, 

 attached to the abdomen in the plate usually occupied by Pelto- 

 gaster, namely, on the left side, near the base of the abdomen. 



The animal (PI. II. fig. 5) has the form of a completely closed- 

 and more or less rounded sac, fixed by one side to the abdomen 

 of the Pagurus. The largest specimen was 5 millim. in length, 

 and was of an oval form ; the smaller one was rounded. The 

 surface of the pallium was smooth, and, in the larger specimen, 

 exhibited a slight sinuosity at the lower part where it was at- 

 tached. The pallium was tolerably thick, though more trans- 

 parent than in Sacculina. In the larger individual there was an 

 empty space on one side of the larger extremity. In structure 

 the pallium resembled that of Sacculina. The portion of the 

 parasite which was fixed to the abdomen of the Pagurus (fig. 6 a) 

 was very convex, and had traversed the skin of the Crab. The 

 compact external membrane of the pallium is not continued over 

 the part of the animal which penetrates the skin of the host, 

 but terminates close to this, in a raised, horny, brownish margin, 

 which becomes confounded with the skin of the Pagurus, just as 

 the corneous margins of the organs of adhesion in Sacculina and 

 Peltogaster unite with the skin of the Crustacea to which they 

 are attached. This corneous border may therefore be regarded 

 as the organ of adhesion of this animal. It is presumable that 

 the skin which envelopes the organ of adhesion in the younger 

 individuals of Peltogaster adheres in exactly the same manner 

 to the abdomen of Pagurus. Probably the young SacculincB are 

 also fixed in the same way. Young Peltogasters sometimes 

 have the anterior orifice closed, but they always possess a buccal 

 orifice. There is consequently a great analogy between Clisto- 

 saccus and the young of Peltogaster, and perhaps of Sacadina ; 



* (cXftcrrof, dosed : o-clkkos, sac. 



4* 



