588 SCIENTIFIC RECORD FOR 1882. 



Mimicry hy plume-moths. 



The plume-moths have wiugs cleft into feathery plumes, and when 

 flying remind one of drifting thistle-down. Mr. J. E. Taylor recalls that 

 of about twenty species of Pterophorus whose larval habits are known, 

 one-half feed on composite plants having plumed seeds, and it is there- 

 fore suggested that the wings of the moths, mimicking the down, must 

 be protective to females when depositing their eggs, as well as when 

 they are flying. 



VIII. MOLLUSCOIDS. 



POLYZOANS. 



Barrois (Jules). Embryog6uie des Bryozoaires. Essai d'une tb^orie g^n^rale du 

 d^velopement bas6e siir I'^tude des metamorphoses. Avec 1 pi. Journ. del'Anat. 

 etde la Physiol., 1882. 



. Embryogeny of the Bryozoa; an attempt at a general theory of their devel- 

 opment, [etc. ] With 1 pi. Ann. & Mag. Nat. Hist. (5), p. 265-279, p. 388-403, pi. 14. 



Julieu (J.) Note sur une nouvelle division des Bryozoaires cheilostomiens. Bull, 

 Soc. Zool. France, 6. Ann., j)p. 271-285. 



Hicks (Thomas). On certain remarkable modifications of the avicnlarium in a species 

 of Polyzoan ; and on the relation of the vibraculum to the avicnlarium. Ann. 

 and Mag. Nat. Hist., (5,) v. 9, pp. 20-25. 



M'Intosh (W. Carmichael.) Preliminary notice of C^phalodiscus, a new type allied 

 to Prof. Allman's Rhabdopleura, dredged by H. M. S. " Challenger." Ann. and Mag. 

 Nat. Hist., (5,) V. 10, p. 337-348. 



A new Bhahdopleuran. 



A new genus of Ehabdopleurse, an order of Polyzoans hitherto only 

 known through one genus — Rhabdopleura — has been made known by 

 Professor Mcintosh. It has been named Cephalodiscus. It is especially 

 distinguished by remarkable branchial or tentacular plumes and by the 

 perfectly free condition of the polypides. It may be added that Profes- 

 sor Lankester visited Norway in August expressly to study Rhabdo- 

 pleura, and was successful in finding it in considerable numbers and 

 under favorable conditions. 



Variations of the avicnlarium in Polyzoans. 



As the Rev. Thomas Hincks well remarks, " The homology between 

 the curious avicularian [or bird-head-like] appendage which is present 

 on so many of the cheilostomata and the zocecium with its contained 

 zooid has been amply demonstrated and is now generally admitted. 

 Indeed the rudimentary or primary forms of the organ exhibit so slight 

 an amount of divergence from the ordinary cells that we have no diffi- 

 culty in recognizing the morphological relationship between the two; 

 and from this starting point a series of transitional forms conducts us 

 to the most highly specialized term, in which the zooecial type is 

 effectually marked." Further, ''the avicnlarium with more or less 

 elongated mandible is a step towards the second of the appendicular 

 organs with which the Cheilostomatous Polyzoa are furnished, the 



