LIVING BRACHIOPODA. 351 



nepliridia and genitalia, and the oblique and posterior occlusor muscles ; this region may 

 he called the perivisceral cavity. For simplicity of reference, these cavities have been 

 mentioned under the general name of coelomic cavity. The difference between the first 

 and second gourd-shaped outline is slight ; in fact, in a comparison with a double 

 gourd-shaped wine bottle of the Japanese, the first division might be regarded as a very 

 wide neck to the bottle. The constriction between the second and third, or largest bulb, 

 is not only indicated by a deep indentation but organically it is the most marked region of 

 the three cavities, for at the junction of these two outlines are seen the gastro-parietal 

 muscles, the otocysts, and the great openings of the main pallial sinuses. 



The two broad pallial sinuses, so characteristic of all the Lingulidae, start from the 

 perivisceral cavity at its junction with the perigastric cavity (53: 1, o. s.) . The openings 

 to these sinuses are large and narrow and stand ol)lique to the median line of the Ijody ; 

 indeed they follow the. outline of the perivisceral cavity above alluded to. The two 

 main sinuses run to the anterior portion of the pallium, and, in Glottidia (53 : 1 ) , make 

 a graceful outward curve at the start and then a slight inward curve. The anterior ter- 

 minations of these sinuses are only one third the distance apart which separates them at 

 their origin. On the inner side of these sinuses there start short lacunae reaching nearly 

 to the methan line and slightly inclined anteriorly. On the outer side of the sinuses 

 there spring from nine to eleven lacunae having the same anterior inclination and reach- 

 ing nearly to the base of the setae in the lateral margin of the pallium. From these 

 lacunae there arise the gill lappets, or ampullae, the discovery of which I first amiounced 

 in 1870. These number from five to eight in each lacune depending upon the length 

 (53: 3). The gill ampulla nearest the median line is largest, and the others diminish in 

 size as they approach the lateral margin. They are very transparent and the blood cor- 

 puscles may be plainly seen flowing through them (52: 7). Ph. Fran9ois ('!J1), in his 

 brief note on L. (inathui, says, in italics, that he did not find the gill ampullae as de- 

 scribed by me, and from the way he expresses it, indicates that he was rather inclined to 

 question their presence in any of the Lingulidae. It may also be added that I failed to 

 find them in L. anntina, nor were they observed in the little transparent L. lepidula, a 

 species which outwardly so closely resemljles Glottidia. The gill ampullae of Glottidia 

 may well be considered another strong generic character. The folds observed by Vogt in 

 the pallium of L. (t)intina were prol)ably due to a contraction of the parts in alcohol. 

 The effect of alcohol in causing the sinuses to bulge may be seen in a section of Glottidia 

 (47: 3). Between these gill-bearing lacunae is a brown pigmentation which unites with 

 the brown lateral margin of the palliiua (39 : 4 ; 53 : 2) . The current passes outwardly 

 along the inner side of the great pallial sinus, running into all of the inner lacunae in 

 turn, then, reaching the anterior end of the sinus, it returns on the outer side, running 



