42 "ENDEAVOUR" SCIENTIFIC RESULTS. 



jointed stem and replacing a hydrocladium. Hydrocladia 

 alternate, one on each internode, both series directed slightly 

 towards the front and rising at an angle of about 40 ; nodes 

 slightly oblique. 



Hydrothecas at an angle of about 40, nearly cylindrical in 

 their distal half, narrowed towards the base ; a very slight fold 

 or ridge near the base on the adcaulinc side, directed a little 

 forward; border with a large pointed straight or slightly in- 

 curved anterior tooth, and a large triangular tooth near the 

 middle of each side ; an angular lobe at each side behind the 

 lateral sarcotheca ; back excavated, adnate. Hydrothecal 

 internodes with the two septal ridges usually scarcely indicated, 

 but with the thickenings at the base of the intrathecal fold and 

 the lateral sarcothecas conspicuous. 



Mesial sarcothecas about three-fourths the length of the 

 hydrothecaa and adnate throughout, aperture oblique. Lateral 

 sarcothecaa tubular, directed forward and slightly outward, 

 scarcely projecting beyond the hydrotheca-margin, aperture 

 small, round, canaliculate. Cauline sarcothecaa broad, completely 

 open above, very thin, two on the rachis at the base of each 

 hydrocladium. 



Gonangial pinnas generally in pairs, each replacing a 

 hydrocladium, with the first four or frve Intel-nodes bearing 

 sarcotheca? only. Corbula? (female) long, cylindrical, con- 

 sisting of up toabout twenty pairs of alternate ribs, springing from 

 separate internodes of the rachis as narrow pinmiles, but expand- 

 ing above into broad leaflets which unite to form a closed 

 corbula ; the distal margin of each leaflet continued a little 

 beyond the line of union so as to form a free-edged narrow 

 extension or wing bordered with sarcothecae and mostly more or 

 less widened upward, especially in those about the middle of the 

 corbula, which expand into a wide lobe with sarcothecaa on both 

 edges ; a large stout lateral spur projecting outward and forward 

 from the distal edge of each rib just above its origin and bearing 

 about six sarcothecas but no hydrothecas ; the end of the rachis 

 projecting a little beyond the corbula, curved upwar-d, armed 

 with sarcothecae : (male) rather narrower, with the free lobes of 

 the leaflets only slightly developed or entirely wanting, lateral 

 spurs much smaller ; the main leaflets becoming gradually 

 shortened and finally separate in the distal part of the corbula, 

 till at the end they are abbreviated close down to the lateral 

 spurs. 



Colour. Bright chestnut brown. 



