138 



REPORT OF NATIONAL MUSEUM, 1910. 



Clark, Austin Hob art — (continued. 



dages; the addition of half of a pair l)e- 

 tween the two elements of the anterior 

 pair, at first by mutation, as in the speci- 

 men of Platysamia cecropia figured, caused 

 in these sessile animals no inconvenience, 

 and therefore became fixed, resulting in a 

 more or less perfect pentamerous sym- 

 metry in which the odd (anterior) ray Is 

 always the most primitive in structure 

 and the least stable in appearance, being 

 frequently absent, while the other rays 

 are invariably present. 



Echinoderm larvae are bilaterally ,«ym' 

 metrical; but they are in all essentials 

 highly specialized animals of quite a 

 different class, fitted for an entirely differ- 

 ent mode of existence, and are only com- 

 parable to the adults, ontogenetically and 

 phylogenetically, in the same way as in- 

 sect larvae are comparable to adult insects. 

 The eclilnoderms in their life phases and, 

 in general, in their structure, are more or 

 less strictly comparalde to those insects 

 which undergoacomplete metamorphosis. 



An interesting structural analogy. 

 Ann. Mag. Nat. Hist., 8th ser., 5, 

 Apr., 1910, pp. 3.58-361, figs. 1,2. 

 Attention is called to the curious simi- 

 larity between the so-called "side-" and 

 "covering-plates" of crinoids and the 

 "snow-shoes" of certain grouse, as seen 

 in Bonasa umbellata. The perfect devel- 

 opment of these plates in deep water 

 forms only is noted, and correlated with 

 the fact that they feed only upon dead food 

 particles which fall upon these plates and 

 glance from them into the ambulacral 

 grooves. 



The phylogenetic interrelation- 

 ships of the recent crinoids. 



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

 1732, May 3, 1910, pp. 115-118. 

 This paper treats of the phylogenetic 

 interrelationships of the recent crinoids 

 without regard to their fossil representa- 

 tives: the characters chiefly employed are 

 found in the stem and in the basals. 



On the type specimen of the 



crinoid described by Mliller as Alecto 

 purpurea. 



Proc. Biol. Soc. Washington, 23, 

 May 27, 1910, pp. 95-98, 1 fig. 

 The type specimen of A lecto purpurea, 

 described by Prof. Johannes Miiller in 

 1841, is described in detail and figured. 

 The species is quite distinct from any 

 other known form, though nearly related 

 to the A sterias pectinata of Linnaeus. It 

 occurs, so far as now known, only in 

 Queensland. 



Clark, Austin Hobart. On the origin 

 of certain types of crinoid stems. 



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

 1740, JuneC, 1910, pp. 211-210. 

 The origin of the crinoid stem from the 

 primitive Jorsocentral echinoderm plate 

 is traced and all the various types are 

 shown to converge toward it. The ab- 

 sence of this plate in the so-called " Pa- 

 laeoechinoidea " is explained by the great 

 specialization of the test in this group 

 whereby thisprimitive structure has been 

 lost, though persisting in the less special- 

 ized recent forms. 



A new Australian crinoid. 



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

 1743, June 7, 1910, pp. 275-276. 

 A new species of Compsomctra, C.lacer- 

 tosa, is descriljed from Port Jackson, New 

 South Wales, the tj-pe being in the Aus- 

 tralian Museum at Sydney. This species 

 was mentioned by P. IT. Carpenter in 

 1890, but was not diagnosed by him; his 

 specimens were from Port Phillip. 



The strict application of the law of 



priority to generic names. 



Science (n. s.), 31, No. 787, Jan. 28, 

 1910, pp. 145,140. 

 The preliminary results of an exhaustive 

 canvass among scientific men to deter 

 mine the existing sentiment in regard to 

 the strict application of the international 

 code of nomenclature is given, and it is 

 shown that some modification of the code 

 is urgently called for because of the de- 

 plorable results of the application of it in 

 its present form. 



Fisher, Walter K. New Pterasteridse 

 from the North Pacific. 



Ann. Mag. Nat. Hist., 8th ser., 5, 

 Feb., 1910, pp. 167-170. 

 Describes four new species of Pteraster 

 and two of HymenaMcr, and gives keys, 

 including other North Pacific species. 



New genera of starfishes. 



Ann. Mag. Nat. //is?., 8th ser., 5, 



Feb., 1910, pp. 171-173. 



Describes four new genera, Thrissacan- 



thias, Gephyrcaster, Sphscriodiscus, and 



Heterozonias, and defines the limits of 



Pentagonaster, Tosia, and others. 



New starfishes from the North 



Pacific. — I. Phanerozonia. 



Zool. A nzeiger, 35, No. 18, Mar. 29, 

 1910, pp. 545-553. 

 Thirteen new species and two new sub- 

 species are diagnosed and keys are given 

 including all of the North Pacific species 

 of Dipsacaster, Benthopecten, and Acan- 

 tharchaster. 



