467 



canal eventually ends in the easily observable anus placed nearer the 

 dorsal than the ventral surface, on the right side of the body. The 

 rudimentary mesentery, and the lateral gastro-parietal and ilio-parietal 

 bands of Lingula are described. There is no median gastro-parietal 

 band. Fsecal matter rolled into round pellets is commonly obser- 

 vable in the intestine of Lingula, while no faeces are ever found in 

 that of the articulated Brachiopoda. 



The genitalia in the articulate Brachiopoda are developed between 

 the two membranes of which the inner wall of the pallial sinuses in 

 which they are contained is composed, and, thrusting the inner of the 

 two membranes from the outer, form a prominent mass connected by 

 a band with the inferior wall of the sinus. The genital artery runs 

 along the upper or outer edge of the band, and the genitalia are 

 developed round it. 



In Lingula the reproductive organs are withdrawn from the man- 

 tle and lodged within the visceral chamber, forming four irregularly 

 lobulated or branched masses, two above and two below the alimen- 

 tary canal, so that they may be distinguished as dorsal and ventral 

 genital masses. The dorsal ovaries are suspended by the ilio-parietal 

 bands, and the ventral by the continuation of these bands along the 

 free margins of the pseudo-hearts. In both cases the attachment is 

 along the margins of the bands, which are related to the genitalia 

 much in the same manner as the suspending membrane is to the 

 genital bands in Waldheimia ; and it would seem that in Lingula 

 the reproductive organs are really developed between the two layers 

 composing the ilio-parietal bands. The author adduces arguments 

 to show that the Lingulce are hermaphrodite, the testis being a red- 

 dish mass, which ramifies over the true ovary. 



The ova probably make their way out by the so-called "hearts," 

 which open by their apices into the pallial cavity, and by their patu- 

 lous bases (the so-called auricles) into the perivisceral chamber, and 

 are hence capable of performing the functions of oviducts. The 

 author has assured himself of the constant presence of the apical 

 aperture of the pseudo-heart in all Brachiopoda. As pointed out by 

 Prof. Huxley, there are four of these pseudo-hearts in Rhynchonella, 

 but only two were found in the other Brachiopoda examined. 



The pseudo-hearts have nothing to do with the propulsion of the 

 blood, a function which is performed chiefly by the pyriform vesicle 



