Hemarks on the Genus Conchicolltes of Nicholson. 9 



Distinguished from C. gregarim "by its greater average length, and 

 much greater diameter, by its much less closely crowded habit, aud by 

 its much more strongly marked annulations.'' 



After Prof. Nicholsou had founded the genus Conchicolltes for these 

 singular Tubicolar Annelides in March, 1872, he founded another 

 genus, to wit, Ortonia, in October, 1872, for the reception of other 

 Tubicolar Annelides that do not seem to be removed from Conchicolites 

 by more than specific differences. An examination of the three species 

 described by him in any good cabuiet in this city^ to wit, C. corrugatus 

 0. conica, and 0. minor, and a comparison with his descriptions of each 

 of them must convince a person that they all belong to the same genus 

 Conchicolites, and if, as generally believed, Odonia conica is the same 

 that Prof. Hall has had from this place, and identified with Tentaculites 

 flexitosa of New York, which name it has borne here for man}' years, 

 the names will be, when written in full, Conchicolites corrugatus, Con- 

 chicolites flexuosa, and Conchicolites minor. 



The following is the generic description of Ortonia : 



Genus Ortonia (Nicholson), October, 1872. [London Geological Mag- 

 azine, vol. ix., p. 446.] 



" Animal solitary, inhabiting a calcareous tube, which is attached 

 along the whole of one side to some foreign body. Tube slightly flex- 

 uous, conical, in section cylindrical, or somewhat flattened laterally, 

 and subtriangular. Walls of the tube thick, cellular along the surface 

 opposite to the attached portion, markedly annulated along the sides." 



" In shape the tubes are markedly conical, their section being circu- 

 lar, or at times somewhat trigonal. Almost all the tubes, though in 

 the main straight, are more or less curved and bent toward their 

 smaller, closed extremities. The widest extremity of the tube opens by a 

 more or less nearly circular aperture ; and the continuity of the tube, 

 from its open to its closed extremity, is not interrupted by any internal 

 septa. The surface-characters of the tubes are of a very remarkable 

 character. Upon the surface, diametrically opposed to that along 

 Avhich the tube is attached to the shell, the tube is of a cellular char- 

 acter, 'exhibiting numerous rounded pits or alveoli, which strongly 

 remind one of the peculiar cellular structure of the tube of Cornidites. 

 This peculiar structure occupies a narrow belt running down the tube, 

 along its dorsal or free surfiice ; and from both sides of this belt there 

 proceeds a series of strong, annular ridges, or rings, which pass round the 

 tube, to disappear on its fixed margin. These rings are not separated 

 by secondary intermediate annulations, nor do they exhibit any longi- 

 tudinal striatiou. Sections of the tubes, however, show that these 



