&8 REPORT OF THE SECRETARY. 



In this memoir there is described and illustrated the young of two kinds of 

 crayfishes, one from Oregon and one from Maryland, representing the two most 

 diverse forms in North America. The first, second, and third larval stages are 

 determined, and there is described the hitherto unknown nature of successive 

 mechanical attachments of the offspring to the parent. 



1723. The Apodous Holothurians. A Monograph of the Synaptidse and Molop- 

 adiida?. Including a report on the representatives of these families in the 

 collections of the United States National Museum. By Hubert Lyman Clark. 

 Quarto. Pages 218+ , with 13 plates. Part of Vol. XXXV. In press. 



This memoir gives a summary of present knowledge of the two families of 

 sea cucumbers, which lack tube feet. 



The most important feature of the work is the recognition of the changes 

 taking place in the maturing and senescence of individual holothurians, par- 

 ticularly in the family Molopadiidae. As a result of this, radical changes in 

 nomenclature have been necessary, but every effort has been made to have the 

 system adopted accord with the most widely accepted codes, and thus be as 

 stable as possible. Special attention has been given to geographical distribution, 

 but the work in this line is chiefly of value as a summary of our present very 

 inadequate knowledge. Artificial keys to genera and species have been freely 

 used with the intention of making the work as useful as possible to all subse- 

 quent investigators, and the numerous figures, most of which are copied from 

 other writers, are given with the same end in view. 



11. Smithsonian Miscellaneous Collections. 



In the series of Smithsonian Miscellaneous Collections there were published 

 24 papers in the Quarterly Issue, Vol. Ill, Parts 3 and 4, and Vol. IV, Part 1, as 

 follows : 



1656. Smithsonian Miscellaneous Collections. Quarterly Issue. Vol. Ill, 

 Part 3 (containing Nos. 1657-1664). Octavo. Pages 241-379, with plates 



LIX-LXIII. 



1657. The Species of Mosquitoes in the Genus Megarhinus. By Harrison G. 

 Dyar and Frederick Knab. Published September 27, 1906. Octavo. Pages 241- 

 258. 



1658. A Contribution to the Knowledge of some South American Hymenop- 

 tera, chiefly from Paraguay. By C. Schrottky. Published February 4, 1907. 

 Octavo. Pages 259-274. 



1659. Description of a New Squirrel of the Sciurus prevostii Group- from Pulo 

 Temaju, West Coast of Borneo. By Marcus Ward Lyon, jr. Published Febru- 

 ary 4. 1907. Octavo. Pages 275-276. 



1660. The Squirrels of the Sciurus vittatus Group in Sumatra. By Marcus 

 Ward Lyon, jr. Published February 4, 1907. Octavo. Pages 277-283. 



1661. A study of the Butterfly Wing- Venation, with special regard to the 

 radial vein of the front wing. By Thomas J. Headlee. Published February 4, 

 1907. Octavo. rages 284-296, with plates lix-lxiii. 



1662. Some Noteworthy Extra-European Cyprinids. By Theodore Gill. Pub- 

 lished February 4, 1907. Octavo. Pages 297-340. 



1663. A review of the American Volutidse. By William Healey Dall. Pub- 

 lished February 4. 1907. Pages 341-373. 



1064. Notes to Quarterly Issue. Vol. III. Part 3. Octavo. Pages 374-379. 



1695. Smithsonian Miscellaneous Collections. Quarterly Issue. Vol. Ill, 

 Part 4 (containing Nos. 1696-1701). Octavo. Pages 381-567, plates lxiv-lxx, 

 and table of contents and index to Volume III of the Quarterly Issue. 



1696. The breeding habits of the Florida alligator. By Albert M. Reese. 

 Published May 4, 1907. Octavo. Pages 381-387, with plates lxiv-lxv. 



