LIST OF PUBLICATIONS. 



137 



Clark, Austin Hob art — Continued. 



The loUowing new suborders are sug- 

 gested: Comatulida Innatantes, ComaUi- 

 lida Oligophroata, Comatulida Macro- 

 phreata. 



A new type of ariiculation, called the 

 pseudosyzygy, is described and discussed. 



The nonmuscular articulation of 



crinoids. 



Amer. iVa<«roZw«,43,No.511, Oct., 

 1909, pp. 577-587, figs. 1-14. 

 A dissertation upon the phylogenotieal 

 significance and systematic importance of 

 articulations, showing that articulations 

 consisting only of ligaments probably 

 arose through a doubling of the more 

 primitive muscular articulations coupled 

 with a loss of the muscles, possibly corre- 

 lated with the transition from a biserial to 

 a monoserial type of arm. 



A new European crinoid. 



Proc. U. S. Nat. Mus., 38, No. 

 1749, June 18, 1910, pp. 329-3.33, 

 A new species of Antedon, A. adriatica, 

 is described from Trieste, and its embry- 

 ology is compared with that of A . mcditer- 

 ranea as worked out by Bury and Barrois, 

 and of A. bifida as worked out by Wyville 

 Thomson and the two Carpenters. It is 

 suggested that possibly the latter did not 

 err in denying the presence of underbasals 

 in A . bifida. 



A proposed di\ision of the Phylum 



Echinodermata. 



Proc. Biol. Soc. WasMngton, 22, 

 Oct. 30, 1909, pp. 183, 184. 

 The Crinoidea are shown to be most 

 nearly related to the Echinoideaand Holo- 

 thuroidea, and are placed with them in the 

 subphylum Echinodermata Heteroradia- 

 ata, in contradistinction to the Asteroidea 

 and Ophiuroidea, which are united to 

 form the subphylum Echinodermata 

 Astroradiata. 



The affinities of the Echinoidea. 



Amer. Naturalist, 43, Nov., 1909, 

 pp. 682-<38G. 

 This is an elaboration of the pre\ious 

 paper. 



On a collection of crinoids from the 



Clark, Austin Hob art — Continued. 



port, Mr. Svend Gad. In the introduc- 

 tion many features of ecology and distri- 

 bution are discussed at length, and in an 

 appendLx is given a list of the crinoids 

 known from Singapore. A small parasitic 

 gasteropod was found on one of the speci- 

 mens, which Is described by Dr. Paul 

 Bartsch in a short paper following the 

 above. 



Origin of the crinoidal muscular 



Zoological Museum of Copenhagen, in- 

 cluding the description of a new species 

 of Eulima, by Dr. Paul Bartsch. 



Vidcnsk. Medd.fradcn Naturhist. 

 Forening i KfSbcnhavn, 1909, pp. 

 115-194. 

 This is a detailed account of a large col- 

 lection of comatulids including many of 

 the specimens which served as a basis for 

 Professor Liitken's MS. names. A large 

 number of the specimens were taken at 

 Singapore by the Danish consul at that 



articulations. 



A mer. Journ. Set., 29, Art. 2, Jan., 

 1910, pp. 40-44, figs. 1-5. 

 The derivation of the complex muscular 

 articulations of the crinoid arm from the 

 simple connectives of simple ambulacral 

 plates such as those of the echinoids is 

 traced. The muscle bundles are, collec- 

 tively, the equivalent of the intersomatic 

 muscles of the echinothurids or the longi- 

 tudinal muscles of the holothurians, and 

 are not, as is commonly supposed, derived 

 indirectly from amorphous connective 

 tissue. 



A new crinoid from the Solomon 



Islands. 



Proc. Biol. Soc, Washinfflon, 23, 



Mar. 23, 1910, pp. 7, 8. 



A new species of Colobometra, C. dia- 



dema, is described from Ugi, Solomon 



Islands. The type is in the Australian 



Museum, Sydney, N. S. W. 



The probable origin of the crinoidal 



nervous system. 



Amer. Naturalist, 44, Apr., 1910. 

 pp. 24.3,244. 

 The nervous system of the crinoids is 

 derived directly from that of the arthro- 

 pod, or, rather, from the common echino- 

 derm-arthropod ancestor, as a result of the 

 progressive shortening of the antero-pos- 

 terior axis of the body, which has culmi- 

 nated in a sessile habit and, further, in a 

 pentamerous radial sjTnmetry. The ner- 

 vous system of the crinoids is shown to be 

 essentially the same as that of the arthro- 

 pods, and the orientation of the crinoids 

 and the arthropods is compared. 



Remarks on the pentamerous sym- 



metry of the crinoidea. 



Amer. Journ. Sci., 29, Apr., 1910, 

 pp. 353-357, 1 fig. 

 The pentamerous symmetry of the 

 crinoidea is derived from that of the 

 bilaterally symmetrical animals by the 

 interpolation, between the two elements 

 of the anterior pair of appendages, of an- 

 other element equal to one-half of that 

 anterior pair. Echinoderms are derived 

 from bilaterally sjTimietrical animals very 

 near the arthropod stock, which possessed 

 an anterior and a posterior pair of appen- 



