55 



SPECIAL REMARKS. 



After having examined numerous specimens of Actinocrinus 

 gibsoni we are able to say that it is a true Actinocrinus with no near 

 affinity to an Eretmocrinus or any species of Batocrinus. 



In describing Goniasteroidocrinus lyonanus it was suggested that 

 the functions performed by the lateral prolongations from the vault 

 the "pseudo-ambulacral appendages"' of Meek, might not be essen- 

 tially distinct from those performed by the proboscis in other genera. 

 This view we have not entertained since the study of the genus 

 Dolatocrinus, as may be seen from our remarks under that genus, 

 and also under Batocrinus, and under the definitions of Gilbertso- 

 crinus greenei and Goniasteroidocrinus faberi. We now regard 

 them as ovarian extensions. If the pores, which we have called 

 ovarian, are really ovarian pores, there would be little doubt about 

 these extensions from the vault belonging to the ovarian system. 

 The great difficulty, that surrounds the assertion that they are 

 ovarian, is the fact that some species do not have any visible pores. 

 The proboscis in Poteriocrinus circumtextus is full of pores, and we 

 have seen them in the proboscis of other species. Where the pores 

 are, in the vault, between the arms, as in Batocrinus, we have not 

 seen them penetrating the proboscis. All of which tends to show 

 that the pores, at the margin of the calyx, at the bases of the arms 

 and penetrating the proboscis performed similar functions, and if 

 one is ovarian all are. If all this is a correct interpretation of the 

 function of these orifices, it leads to the conclusion that genera, 

 having pores at the angles of the plates of the calyx and not else- 

 where, were in possession of ovarian pores that discharged through 

 the calyx itself. 



Batocrinus nodosarius occurs at Sedalia, Missouri, and also in 

 Adams county, Illinois. 



