DEPARTMENT OF MARINE BIOLOGY. 175 



Scientific Equivalents for the Common Names of Birds, etc. — Continued 



Parula warbler = Compsothlypis umeri- 



cana americana. 

 Cape May warbler = Dendroica tigrina. 

 Black-throated blue warbler = Dendroica 



cierulescens ca^rulescens. 

 Myrtle warbler = Dendroica coronata. 

 Black-poll warbler = Dendroica striata. 

 Pine warbler = Dendroica vigorsi. 

 Yellow palm warbler = Dendroica palma- 



rum hypochrysea. 



Water thrush = Seiurus noveboracensis 

 noveboracensis. 



Mourning warbler = Oporornis Philadel- 

 phia. 



Florida yellow-throat = Geothlypis trichas 

 ignota. 



Redstart = Setophaga ruticilla. 



Catbird = Dumetella carolinensis. 



Olive-backed thrush = Hylocichla ustulata 

 swainsoni. 



Report upon Investigations at Tortugas, by L. R. Canj. 



The measurement of specimens of three species of gorgonians growing 

 under natural conditions on the reefs about Loggerhead Key was made 

 this season to continue a record started in 1910. On all of the reefs the 

 number of specimens not more than two years old was found to be much 

 greater than at any previous season since these records have been kept. 

 When the measurements were made in 1911 very few young specimens were 

 found, while in 1912 many year-old individuals were found, but few of the 

 age of two years. The records for the present season show that a normal 

 number of one and two year old individuals were present on the reefs for 

 the first time since the almost complete destruction of small specimens bj^ 

 the hurricane of October 1910. The measurements and photographing of 

 specimens of gorgonians previously cemented upon tiles were continued and 

 new tiles, bearing individuals of different ages, were photographed and 

 fastened with pins upon the reefs. 



A series of experiments involving more than 100 individuals of Cassiopea 

 was carried out to determine whether or not, other factors being constant, 

 muscular activity has any influence upon the rapidity with which new tissue 

 is regenerated to repair an injury. In one set of experiments one member 

 of each pair of medusae was rendered inactive by the removal of its marginal 

 sense organs, which control muscular activity ; while from the other member 

 of the pair an equal amount of tissue was removed from between the sense 

 organs, leaving the medusa active. In another set of experiments the sense 

 organs were removed from one-half the bell-margin, while from the other 

 half the tissue was removed from between the sense organs. A narrow 

 strip of ectodermal tissue was removed from the subumbrella surface of the 

 bell, thus insulating the two halves so that the one from which the sense 

 organs had been removed remained inactive. In a third experiment a 

 single sense organ was left upon one half of the bell margin and the two 

 halves insulated in the manner just described. In all the experiments a 

 circle of tissue of constant diameter was removed from the center of the 

 disk and the amount of regeneration measured from the edges of this cut. 

 In every instance where one half of the medusa was active and the other 

 inactive regenerated tissue became noticeable first upon that half which was 

 active. In the pairs which consisted of an active and an inactive individual 

 regenerated tissue first became apparent in the active specimen. Where a 

 single sense organ was left upon one half of the bell-margin the regeneration 

 took place with equal rapidity from the two halves. In the later course of 

 the experiments the amount of regeneration was about equal from the two 

 halves, so that the point of closure in the disk of new tissue lay eccentrically, 

 being always closer to the side which had been inactive, and from which the 

 growth of new tissue had been slower in starting. 



Individuals of both sexes of Centrechinus setosum -mth ripe sexual products 

 were obtained in abundance during the last week in September. The eggs 



