8 Remarks on the Genus ConchicoUtes of Nicholson. 



space of a line or more ; and either partially free, or contiguous to one 

 another throughout the remainder of their course. Length of the 

 fully grown tube ^ inch or a little more ; diameter of tube at mouth 

 J^th inch. Tube composed of conical, imbricating rings, about forty in 

 the space of an inch (about four in the space of f^h inch), giving 

 the tube a strongly annulated appearance " 



The specimen figured and described as above was from the collection 

 of Dr. H. H. Hill, of this city, though he received no cre'dit for it, 

 and was found on the hills back of Cincinnati, where other specimens 

 have also been found. Prof. Nicholson says of the specimen further : 



" The exquisite preservation of the specimen from which the above 

 description is taken enables me to settle definitely certain points con- 

 nected with the structure of ConchicoUtes, about which my specimens of 

 C. gregarius had left me in doubt. It is now certain, as I had pre- 

 viously conjectured, that the tubes in this genus agree with those of 

 the modern Serpulce in being calcareous, and that they differ altogether 

 from the extinct genus Cornul'des, in being altogether destitute of any 

 cellular structure. They differ from Serpulce in having the tubes com- 

 posed of a succession of imbricated rings, the wider ends of which are 

 directed toward the .mouth of the tube. From the extinct Ortonia, 

 again, they differ not only in the circumstance just mentioned, but in 

 their social clustered habit of growth, and in the fact that the tube is 

 not attached along the whole of one of its sides." 



"The specimen exhibits the tubes of more than thirty individuals 

 of ConchicoUtes corrugcdus attached to the spire of Cyclonema hilix, 

 The tubes are all attached to the shell by their smaller ends, and ra- 

 diate from their points of attachment, somewhat like the spokes of a 

 Avheel. Each tube is conical, circular, or nearly so, in section, and 

 widening out gradually from its apex to its mouth. When carefully 

 examined, it can readily be made out that the tube really consists of a 

 succession of short, calcareous rings, of a conical form, inserted one 

 Avithin the other — this structure being especially perceptible in the 

 interior of the broken tubes. From the exterior, however, the appear- 

 ance is more that of a succession of strongly marked ridges or annula- 

 tions, which completely surround the tube, and are separated by slight 

 depressions or flattened interspaces. None of the tubes are perfectly 

 straight, but all are more or less curved, especially toward their at- 

 tached ends. The extent of the attached portion of the tube varies, 

 being mostly from one to two lines. Their unattached portions run 

 generally (in any two contiguous tubes), more or less, nearly parallel to 

 one another ; but though in contact in many instances, it is doubtful 

 if they are actually adherent, and they are most probably not so. 



