278 Dr. P. H. Carpenter on the 



extensive acquaintance with the recent members of the same 

 subkingdom is necessary, than for the interpretation of fossil 

 Brachiopoda, sponges, corals, Mollusca, and fishes, the mor- 

 phology of which cannot have differed in any important 

 respect from that of the recent species. Without such a 

 preliminary study no collector, however zealous, can hope to 

 arrive at any rational conclusion about the functions of the 

 different structures which he may discover by the careful 

 examination of his fossils. 



We have been told, for example, how it is evident from 

 simple inspection that the valvular orifice of the Palasocri- 

 noidea is the mouth, and altogether disconnected from the 

 radial system of water-vessels ; that the calcareous cl supple- 

 mental pore-plates " described by Homer on the ambulacra 

 of Pentremites are the remains of collapsed soft and membran- 

 aceous tentacles, such as occupy the pores of the ambulacral 

 field in Echinoderms ; and that these tentacles communicated 

 not with a single median water-vessel, as in other Echino- 

 derms, but with the hydrospire-apparatus placed at the sides 

 of tlie ambulacra *. 



No educated palaeontologist believes the first of these 

 assertions, which have been put forward, not as expressions 

 of individual opinion, but as positive facts ; and I am convinced 

 that the other two are equally untrue, as I shall endeavour to 

 show subsequently. I merely adduce them here as instances 

 of the errors which I believe to be due to an insufficient 

 knowledge of the morphology of recent types. 



I endeavoured in my previous paper to distinguish between 

 the observations which Mr. Hambach had recorded and the 

 conclusions which he had permitted himself to draw from 

 them. Many of the former I have been able to confirm ; 

 from most of the latter 1 entirely dissent. In a reply to my 

 criticisms, which he has recently published f, he says, " Mr. 

 Carpenter not only expresses great doubts as to the correct- 

 ness of my statements, but has the assurance to refer the 

 results of my observations to a ' wonderful power of imagina- 

 tion.' " I freely admit the use of this last expression, not, 

 however, in reference to the result of any observation, which 

 would be impossible from the nature of the case (as Mr. Ham- 

 bach has never seen a living Blastoid), but to one particular 

 theory which he has still further developed in his recent 

 paper, viz. the supposed " collapse " of the tentacles into 

 limestone plates J. 



* See the woodcut, infra, p. 293. 



t ''Jsotes about the Structure and Classification of the Pentremites" 

 Trans. St. Louis Acad. Sci. vol. iv. no. 3, 18^4, pp. 537-547. 

 \ See p. 292, infra. 



