70 JOURNAL OF THE [March, 



object that delights to grow upon the oyster, which they call 

 "gray-beard," and sometimes "gray-moss." It is one of the 

 Bryozoa. The one that I have often found is Sertidaria argentea, 

 an exquisite creature ; for, though looking like a delicate silvery 

 alga, it is not a plant at all, but a finely branching Zoophyte, or 

 community of exquisite living animal florets. This serves the 

 oyster well, in much the same way as does the red sponge. 



But our oyster has many enemies. The boring yellow sponge, 

 Cliona sulphurea,e2it?,VQry minute holes into the shell, so numer- 

 ous, and so winding, as in some instances to cause the shell to 

 fall in pieces. These minute holes, under the microscope, show 

 gouges at their edges, as if they had been cut with chisels, like 

 post holes. But the process is as yet a mystery. The great 

 winkles, Sycotypus canaliculatus and Fulgiir carica, with their file- 

 tongues will rasp off the nib end of the oyster shell, then intro- 

 duce the sucking siphon, and so consume the moUusk at their 

 leisure. The little drill, Urosalpinx cinerea, is a severe pest. 

 This shell and the two just mentioned are spiral univalves. The 

 drill is a small shell rarely measuring three-fourths of an inch in 

 length, and its lingual ribbon, or file-tongue with its armature of 

 several rows of sharp teeth, is microscopic. I have watched it 

 at work, and I think that the little burglar bores a hole through 

 the oyster's house by crooking its tongue, as I do my finger, let- 

 ting the knuckle represent the bend, or crook of the file-tongue, 

 in which case the teeth would stand out like a brush ; which 

 brush twisted around and back again, in a three-quarter or per- 

 haps entire circle, would represent the action of a drill. The 

 hole is always perfectly symmetrical, and generally is counter- 

 sunk at the place of starting. The hole completed, the tiny 

 siphon tube of the mollusk is introduced, and the soft parts of 

 the oyster are taken up. Sometimes the drum, Pogonias chromis, 

 inflicts severe damage on an oyster-bed. This singular fish has 

 in the upper part of its throat very large, and solid, pharyngeal 

 bones, which are covered with closely set hard round pavement- 

 teeth, not unlike the cobble-stones of old. With its front teeth 

 it picks up an oyster, and it crushes it with the pharyngeal 

 teeth, and then swallows it. This fearful creature gets its name 

 from a booming noise which it is able to make. One year a 

 school of drums entered Raritan Bay, and destroyed many 

 thousands of dollars' worth of oysters in a single night. Except- 



