FLOSCULAEIDiE. 175 



building its case, and at the same time discovered the use of the curious 

 little rotatory organ on the neck. When fully expanded, the head is > 

 bent back at nearly a right a-ngle to the body, so that the disc is placed 

 nearly perpendicularly, instead of horizontally ; the larger petals, which 

 are the frontal ones, being above the smaller pair. Now, below the 

 large petals (that is, on the ventral side) there is a projecting angular 

 chin, which is ciliated ; and immediately below this is the little organ in 

 question. It appears to form a small hemispherical cup, and is capable 

 of some degree of projection, as if on a short pedicle. On mixing car- 

 mine with the water, the course of the ciliary current is readily traced, 

 and forms a fine spectacle. The particles are hurled round the margin 

 of the disc, until they pass off in front through the great sinus, be- 

 tween the larger petals. If the pigment be abundant, the cloudy tor- 

 rent for the most part rushes off, and prevents our seeing what takes 

 place; but if the atoms be few, we see them swiftly glide along the 

 facial surface, following the irregularities of outline with beautiful pre- 

 cision, dash round the projecting chin like a fleet of boats doubling a 

 bold headland, and lodge themselves one after another in the little cup- 

 like receptacle beneath. Mr. Gosse, believing that the pellets of the 

 case might be prepared in the cup-like receptacle, watched the animal j 

 and presently had the satisfaction of seeing it bend its head forward as 

 anticipated, and after a second or two raise it again, the little cup having 

 in the meantime lost its contents. It immediately began to fill again ; 

 and when it was full, and the contents were consolidated by rotation, 

 aided probably by the admixture of a salivary secretion, it was again 

 bent down to the margin of the case, and emptied of its pellet. This 

 process he saw repeated many times in succession, until a goodly array 

 of dark-red pellets were laid upon the yellowish-brown ones, but very 

 irregularly. After a certain number were deposited in one part, the 

 animal would suddenly turn itself round in its case, and deposit some 

 in another part. It took from two and a half to three and a half 

 minutes to make and deposit a pellet. Some atoms of the floating 

 carmine now and then passed down the gullet into the gizzard, and 

 thence into the stomach ; but these were quite independent of, and 

 unconnected with, the pellets, which were composed exclusively out of 

 the torrent that had passed off the disc. On one occasion the cup was 

 brought down to the margin, but, from some cause or other, failed to 

 deposit its pellet ; it was raised for a moment, and then a second 

 attempt was made, which was successful. 



Such is the vivid picture and perfect description of the wondrous 

 mechanism and ingenuity of this singular and beautiful animal. 



