148 Papers from the Marine Biological Laboratory at Tortugas. 



AGLAURA CILIATA, 1 New Species. 

 (Plate 3, figs. 14-16.) 



Specific characters. Aglaura with bell, provided with a prominence at the 

 top ; gastric pouches at upper extremity of manubrium ; four pendulous oral 

 lappets bearing nettling organs and lined with strong cilia. Velum not 

 strongly developed ; tentacles, 24 in number, short and not vigorous ; litho- 

 cysts, 8 in number, placed midway between the marginal endings of the 

 radial canals. Four small masses of glandular tissue hang down from the 

 walls of the manubrium, above the middle, into the lumen of that organ. 

 Eight similar masses hang from the radial canals, one from each canal, into 

 the space within the bell. Color, steely blue, uniform throughout. 



Habitat. Open sea around the Tortugas Islands, Florida. Taken in tow^- 

 net near ship-channel by Dr. W. K. Brooks, July, 1905. The specimens 

 were amongst a quantity of material taken in the tow, and very kindly 

 given to the writer for examination. This opportunity is taken to acknowl- 

 edge my gratitude to Dr. Brooks for this and very many other favors. His 

 helpful suggestions were keenly appreciated. 



The occurrence of the peculiar knotted masses of tissue in the two dif- 

 ferent parts of this medusa, on the radial canals and within the manubrium, 

 with every indication of being glandular rather than gonadial tissue, is of 

 considerable interest. It would not be strange if either or both of these 

 two groups of protuberances had sometimes been mistaken for gonads. 

 Again, the slender pendulous pouches upon the manubrium have undoubtedly 

 been called by that name. On the placing of these organs a distinction has 

 been made between medusae, which were therefore concluded to constitute 

 separate genera. Thus, Haeckel 2 has separated Aglaura and Agalma partly 

 on account of the presence of eight gonads in the latter, located on the radial 

 canals. Aglantha is another genus which is distinguished principally on the 

 basis of this character. The species under discussion partakes of the charac- 

 ters of both Agalma and Aglantha. 



A comparison between the old species Aglaura heinistoma Peron 3 and 

 A. ciliata shows that the differences group themselves as follows : 



Aglaura hcmostoma. Height not greater than breadth. Lips not provided with 

 nematocysts (?). Gastric pouches (" Geschlechtsorgane," Leukart; 4 ' Tentakeln," 

 Eydoux u. Souleyet 5 ) not higher than the middle of manubrium. No glandular pro- 

 tuberances on radial canals or interior of manubrium. 



Aglaura ciliata nezv species. Bell not parallel-sided, higher than broad. More 

 decided apical protuberance than in A. hemistoma. Lips strongly ciliated and set 

 with clusters of nematocysts. Gastric pouches near the upper end of the manubrium. 

 Glandular protuberances projecting from inner walls of manubrium, and pendant from 

 radial canals, near their origin. 



1 Derivation : ciliatits, having cilia. From the character of the inside of the 

 manubrium. 



- Haeckel, E. 1880. System. 



8 Peron. Annales du Museum, t. xiv. 



4 Leukart, Rud. 1856. Archiv fiir Naturgeschichte. 



5 Eydoux u. Souleyet. Voyage de la Pionite. Zool. Zoophyt., Pt. I. 



