352 



THE AMEBIC AN NATURALIST 



[Vol. XLII 



ships of the comatulids. Few zoologists realize how many species 

 of recent comatulids are now known, and it may therefore be of 

 interest to point out that while only four of the new genera 

 proposed are monotypic, five have more than eighteen species 

 each and one of these has over fifty. Mr. Clark's selection of 

 new names for his genera is particularly to be commended, as all 

 are derived from the Greek, terminate in -metra, and are eu- 

 phemistic. 



During the summer, Mr. Clark worked at the Museum of 

 Comparative Zoology and some of the results of his work ap- 

 peared in January in a paper, entitled "Notice of Some Crinoids 

 in the Collection of the Museum of Comparative Zoology." 6 In 

 addition to the description of eight new species, there is an im- 

 portant note on six-rayed crinoids, a key to the genus Bathy- 

 crinus in which eight species are recognized, a table showing the 

 bathymetrical and geographical distribution of Bathycrinus, and 

 finally a "Key to the genera of Antedonidae. " This key is an 

 enlargement and slight rearrangement of the one published in 

 October and includes two additional genera, both of which seem 

 to be well-defined. 



Not content with systematic work alone, Mr. Clark shows his 

 interest in crinoid morphology, and the larger questions involved 

 when the geological history of the class is considered, by a very 

 important paper on "Infrabasals in Recent Genera of the Cri- 

 noid Family Pentacrinitidae, " 7 in which he demonstrates, ap- 

 parently beyond doubt, the presence of infrabasals in Isocrinus 

 decoi-us and Metacrinus rotundus. As no less an authority than 

 Carpenter himself "positively asserts that they do not exist in 

 the recent Pentacrinitidae," this discovery is very interesting. 



Having found how heterogeneous a group the old genus Ante- 

 don is, Mr. Clark's attention was naturally turned next to the 

 equally well-known genus Comatula, and the results are given 

 in ' ' The Crinoid Genus Comatula Lamarck ; with a Note on the 

 Encrimu parrce of Guerin." 8 It is interesting to know that 

 Comatula is far more homogeneous than might have been ex- 

 pected and requires the coinage of no new generic names and the 

 revival of only a single old one, Comaster. The latter however, 

 includes 43 of the 50 species hitherto called Comatula (or Actino- 

 metra). The note on Encrinus parm is important and interest- 



• Bull. M. C. Z., 51, pp. 233-248. 



T Proc. V. S. X. M., 33, pp. 671-676. 



• Proc. T. S. X. M., 33, pp. 683-688. 



