REPORT ON THE CRINOIDEA. 195 



and the Cystids had no such arms, and the Holopodidse and Edriocrinus were stemless. 

 None of the typical Pelmatozoa, however, are devoid of both stem and arms, with one 

 or both of which the chambered organ seems to be correlated. A so-called pedunculate 

 Starfish has already been described by Prof. Perrier,^ and it was with much disappoint- 

 ment that I learnt from Mr. Sladen" that Caulaster is far from being the interesting type 

 which it was at first supposed to be. I am not without hopes, however, that future 

 morphological work upon Urchins and Starfishes may throw more light upon this question ; 

 and there is very much to be done by those who will go into the study of the Palaeozoic 

 Starfishes equipped with a knowledge of the morphology of recent Echinoderms, and 

 will not be content with merely compiling empirical descriptions of new sj^ecies. 



Miiller's original classification of the true or brachiate Crinoids divided them into 

 three groups, Articulata, Tessellata, and Costata, the last including the problematical 

 genus Saccosoma, which may perhaps eventually turn out to be an Ophiurid. Eeference 

 has already been made {ante, pp. 145-147) to the unsuitability of the Mullerian names 

 Articulata and Tessellata for the two other principal divisions of the brachiate Crinoids. 

 The latter is practically co-extensive with the Palseocrinoidea of Messrs. Wachsmuth and 

 Springer.^ These authors have gone further than Zittel and de Loriol, and have pro- 

 posed to divide up the Crinoidea (understood in the widest sense) into the following 

 orders: — (1) Blastoidea ; (2) Cystoidea ; (3) Palseocrinoidea ; (4) Stomatocrinoidea ; 

 (5 ?) Costata. This classification, however, has been by no means generally accepted. 

 Difi"erent as are many of the Palseocrinoids, e.g., Eucalyptocrinus, from a Pentacrinite, 

 others, such as the Ichthyocrinidse, have many of the characters of a recent Crinoid ; and 

 an arrangement which elevates the difference between Pentacrinus and Ichthyocrinus to 

 the same importance as those between Pentacrinus, Pentremites, and Echmosphcerites 

 respectively, appears to me to be founded on a misconception of the value of morpho- 

 logical characters. 



On the other hand, although the definition of the Palseocrinoidea which has been given 

 by Wachsmuth and Springer is capaljle of improvement in one or two respects, it is far 

 more correct and is based upon sounder morphological principles than any definitions of 

 the Tessellata which have been di-awn up by Miiller and his followers. But I cannot 

 regard the two groups Palseocrinoidea and Stomatocrinoidea (Articulata or Neocrinoidea) 

 as equivalent to the Blastoids and Cystids ; so that while keeping the Palseocrinoids at the 

 level of an order, I should rank the Blastoidea and Cystidea as classes, in accordance 

 with the practice generally adopted in this country. 



Prof. Chapman* has proposed a classification of the brachiate Crinoids which "is 



1 Snr une Ast^rie des grandes profondeurs de I'Atlantiq^ue, pourvue d'un piidoncule dorsal, Comptcs rendus, 

 t. xcv. pp. 1379-1381. 



2 The Asteroidea of H.II.S. Challenger Expedition, part ii., Journ. Linn. Soc. Land. (Zool.), vol. xvii. p. 217. 

 5 Revision, part ii. p. 3. 



* A Classification of Crinoids. Trans. Eoy. Soc. Canada, vol. i., 1883. Section iv., 1882, pp. 113-116. 



