178 MR EDWARD T. BROWNE ON 



DISCOPHORA. 



Family PELAGIID^E. 



Pelagia perla (Slabber), 1775. 



Station 542, lat. 37 56' N., long. 29 11' W. 4th July 1904. 



Station 543, Fayal Harbour, Azores. Surface. 5th July 1904. 



Station 544, lat. 39 15' N., long. 26 55' W. (north of the Azores). Surface. 

 7th July 1904. 



Fourteen specimens were taken in Fayal Harbour. The smallest is about 50 mm. 

 in diameter, and the largest about 75 mm. The umbrella is about twice as broad as 

 high, and externally covered with large elliptical warts. The marginal lobes are 

 quadrilateral, with rounded corners, a little broader than long. The oral arms are about 

 twice the length of the radius of the umbrella, and the oesophagus about two-thirds the 

 length of the radius. 



Eighteen specimens were collected at the station north of the Azores. They are all 

 young stages, about 20-30 mm. in diameter, and have roundish warts on the ex- 

 umbrella. At Station 542 a single specimen in very bad condition was taken. 



There is probably only one species of Pelagia in the North Atlantic, though six 

 have been described. 



Family CYANEID.E. 



Desmonema, L. Agassiz, 1862. 



This genus was established by L. AGASSIZ for the reception of Chrysaora gaudi- 

 chaudi, Lesson, which was first discovered during the voyage of the Coquille in 

 Soledad Bay, Falkland Islands, and also near Cape Horn. At the same time AGASSIZ 

 made another new genus called Couthouyia, of which only a very brief account was 

 given. HAECKEL emended the definition of the genus Desmonema so as to include 

 Couthouyia, and added three species, namely, Couthouyia pendula, L. Agassiz ; 

 Cyanea imporcata, Norman ; and a new species called Desmonema annasethe. 

 According to HAECKEL'S definition, -Desmonema differs from Cyanea in having the 

 tentacles arranged in a single row instead of in several rows. 



VANHOFFEN a little later also emended the genus, and rejected HAECKEL'S distinction 

 as to the arrangement of the tentacles, on the ground that Cyanea passes through a 

 stage with the tentacles arranged in a single row. VANHOFFEN'S definition of the genus 

 Desmonema is based upon AGASSIZ'S brief description of Couthouyia pendula, and the 

 genus therefore should have been called Couthoui/ia. According to VANHOFFEN, 

 Desmonema differs from Cyanea in possessing twenty-four marginal lobes. In Desmo- 

 nema the tentacular lobes are not divided as in Cyanea. The gonads are shorter 

 and do not hang down so far as those of Cyanea, and the oral arms taper from a broad 



(ROY. soc. EDIN. TRANS., VOL. XLVI., 242.) 



