166 Cincinnati Society of jSfatural History. 



sideriiig the earl}' appearance of this Genus, and the anomalous 

 character of many divisions of the class to which it belongs, it may be 

 readily understood, that any seeming variations which this fossil pre- 

 sents, when compared with palaeozoic Crustacea better known, instead 

 of tending to rise doubts as to its zoological position, become striking 

 evidences of the modifications which pertain to fossil as well as recent 

 Crustacea, thus leading us to seek the true relations borne b}' these 

 ancient races to the forms now living, and to their contemporaries of 

 the palaeozoic seas. 



While a casual glance at this fossil calls to mind the forms of the 

 pedunculate Cirripedia, there is no relation whatever between them 

 more than that which belongs to creatures of the same class. Nor is it 

 attempted, at this time, to assign this fossil Arthropod to a nearer 

 po->ition than is suggested by the facts given in the description ^of the 

 Genus hereb}^ established. A thorough study of numerous specimens, 

 and of those bearing remains of the appendages, is necessary before a 

 closer relationship can be with certainty assigned. The two specimens 

 found by Prof. Harper, occurred at about three hundred and fifty feet 

 above low water of the Ohio river, at Cincinnati. Those found by Mr. 

 Vallandigham, at about four hundred feet. Mr. Patterson's specimen 

 was found at Oxford, Ohio, and Dr, Newton's in the upper part of 

 the Hudson River Group, at Richmond, Indiana. The specimen found 

 by the writer was from the same horizon as the last, near Osgood, In- 

 diana. Mr. S. A. Miller has in his possession specimens of the same 

 Genus, and apparentlv of the same species, from the Trenton rocks of 

 New York. Mr. Braun, the well-known collector, has a slab contain- 

 ing several specimens, apparently of a different species, in which tlie 

 number of abdominal segments is much greater, and two of which seem 

 to exhibit remains of the lateral appendages. These specimens were 

 found in Indiana. As the slab also contains several fine specimens of 

 Heterocrinus subcrassus^ they are probably from the upper part of the 

 Hudson River Group. The range of the genus is, therefore, as at 

 present known, from the Trenton through the Hudson River Group. 

 It is not improbable that the forms in Mr. Braun's collection may, 

 with careful stud}', give us additional facts in regard to this remark- 

 able ( 'I'ustacean, which is not only the t3'pe of a new Genus and Fami- 

 ly, but, no doubt, of a new Order also. 



The absence of pores, of pectinated rhombs, of any indications 

 whatever of an ambulacral s^'stem, and the fact that these fossils ac- 

 cord in no way with any character of the Cystidew, either figured or 

 described, makes it somewhat renuirkable that they should have been 

 referred to the Echinoderinata. 



