316 Mr. Sowerby on a new 



Art. XXXVI. Note on the foregoing Paper, together 

 with a Description of a new Species of Pentremites, By 

 G. B. Sowerby, Esq^. F.L.S., S^c. 



The almost anomalous form and singular structure of the 

 bodies distinguished by Mr. Say by the name of Pentremite 

 (Pentremites) has been the cause that some attention has also 

 been given to them in this country. The circumstance, however, 

 of all the specimens received in this country from Kentucky, 

 being changed into a sort of calcedoriy or chert, has perhaps not 

 only prevented British Naturalists from forming a correct judg- 

 ment of their natural affinities, as a family, but ap^:^ars also to have 

 had the effect of preventing us from recognizing the generic re- 

 semblance to the species that occur here, which, bearing so much 

 greater a similarity to some of the Echinidce has caused some of 

 our Naturalists to class them together : for it is observable that 

 of perhaps twenty specimens of the " Kentucky Asteriul FossiP 

 that I have examined, only one individual shows the sutures that 

 separate what Say calls the ''pelvic^ scapular and interscapular^^ 

 plates or pieces. The examination of the above mentioned in- 

 dividual, has however suggested to me the probability that part 

 of the three unequal pieces Say calls the Pelvis, may in fact prove 

 to be costalsy because a little protuberance, " at the base of the 

 pelvis" having, " a small rounded surface" being '' perforated in 

 the center for the passage of the alimentary canal," and having 

 '' on the outer margin, very short, but distinct radii of elevated 

 lines evidently intended for articulation with the first joint of the 

 column," is actually divided by a suture from the superior por- 

 tion of what Say calls the pelvis, and in the same manner is sepa- 

 rated into three, distinct, nearly equal portions, and may conse- 

 quently alone form the pelvis ; thus evidencing one more circum-» 

 stance in which the genus is related to the Crinoidea. 



The circumstance of Say's first species, P. globosa, having been 

 brought from England, led me at first to suppose that he might 

 refer to one of those species that has come into my hands ; 

 his description, however, is so incomplete and the terms he has 



