482 



SCIENCE. 



[N. S. Vol. XVII. No. 430. 



The Atlantic Palolo: Alfred G. Mayeb, 



Miiseum of the Brooklyn Institute of 



Arts and Sciences. 



The 'Atlantic Palolo' is Eunice fucata 

 Ehlers. It is found at the Dry Tortugas, 

 Florida, and lives within disintegrating 

 coral rock or coquina from below low tide 

 level to a depth of at least six fathoms. 

 Its breeding habits are closely similar to 

 those of the well known Pacific Palolo 

 worm {Eunice viridis). 



The Atlantic Palolo swarms at the sur- 

 face before sunrise within three days of 

 the day of the last quarter of the moon, 

 between June 29 and July 28. The pos- 

 terior sexually mature end of the worm 

 breaks away from the anterior end, and 

 swims backwards and upwards to the sur- 

 face, where it continues to swim backward 

 with great rapidity until about the time 

 of sunrise, when it contracts, casting the 

 genital products out into the water. The 

 anterior part of the worm remains below 

 in the coral rock, and takes no part in the 

 swarm. The worm requires at least two 

 years to attain sexual maturity. There 

 are 57 per cent, of males and 43 per cent, 

 of females. Only sexually mature worms 

 cast off their posterior ends at the time 

 of the swarm. The immature worms are 

 about twelve times as numerous as the 

 mature. 



The shock produced by cracking the 

 coral rock acts as a stimulus to produce 

 the drama of the breeding-swarm before 

 the normal date of the swarm. Eggs ob- 

 tained in this manner are immature and 

 can not be fertilized, even twelve hours 

 before the time of the normal swarm. All 

 of the eggs mature simultaneously within 

 the swimming worms at the time of the 

 normal swarm. 



The eggs float in the water, are fertilized 

 and begin to segment soon after extrusion 

 from the worm. The segmentation is total 

 and unequal, the gastrula is formed by 



epibole, and the larva is telotrochal. The 

 young larvffi swim near the surface, but 

 sink to the bottom upon attaining four 

 pairs of setigerous lobes. The posterior 

 segment of the larva bears a pair of dorsal 

 as well as a pair of ventral cirri. Only 

 the ventral pair of cirri persist in the fully 

 developed worm. 



An Aberrant Botatorian: T. H. Montgom- 

 EBY, Jr., University of Pennsylvania. 

 (Read by title.) 



Dimorphic Queens in an American Ant 

 {Lasius latipes Walsh) : W. M. Wheel- 

 er and J. F. McClbndon, University of 

 Texas. (Published iu the Biological 

 Bulletin, Vol. IV., No. 4, March 1903, 

 pp. 149-163, 3 Figs.) 

 A colony of Lasius latipes observed near 

 Rockford, Illinois, during the nuptial 

 flight (September 17, 1902) was found to 

 contain numerous virgin queens of two 

 different types. One of these (the '/5-fe- 

 male') was the fulvous red, remarkably 

 hairy and flat-legged type, with very short 

 tarsi, that has been heretofore regarded as 

 the female of latipes. The other ('a-fe- 

 male') was dark brown, less hairy, with 

 much less flattened legs and decidedly 

 longer tarsi. The a-type was also found 

 in material from two nests of latipes col- 

 lected in a very different locality (Cole- 

 brook, Connecticut) during August, 1901. 

 No transitions between the two types were 

 observed in any of the nests. The follow- 

 ing hypotheses may be advanced to account 

 for the occurrence of the two different 

 queens in the same colony: (1) One of 

 these may be supposed to be the female 

 of a species parasitic on latipes. (2) The 

 iJ-female may represent merely a diseased 

 condition of the a-female. (3) The «- 

 form, in pilosity and structure, is so clearly 

 intermediate between the /9-form and the 

 female of Lasius claviger Roger as to sug- 



