1903. J MEDUSJ5 FROM BRITISH COLUMBIA AND ALASKA. 169 



The base of the stomach is small, gradually enlarging into a 

 cylindrical proboscis, which extends from nearly two thirds to 

 the whole length of the bell. In the contracted condition it is 

 more spindle-shaped. The month is small and circular, without 

 lobes or folds. . „ , 



The radial canals are four simple tubes running from the 

 highest point of the stomach to the circular canal. The latter runs 

 near the inner wall of the bell and makes the quadrangle that is 

 seen from the under surface in Agassiz's figure (2, p. 178) ot 

 S. reticulatum. No gonads are to be distinguishecL 



Colour.— Bell light brown, proboscis yellow, ocelli black. 



Habitat.— Yictorin Harbour, collected by Shearer. 



Biscussiooi.— The presence of urticating-organs on the exum- 

 brellar surface of the bell (unless they are arranged m a definite 

 manner retained in the adult stage) used ds a generic character 

 by Haeckel (18) is invalidated by the fact that these structures 

 occur in many young Medusfe, e. g. Aurelia flavidula, Dmematella 

 cavosa (Fewkes), Proboscidactyla Jlavicirrata, Gonionemoidesgeo- 

 phila, PolyorcMs penicillata, and the young of Sarsia. This is 

 emphasised by Agassiz's statement that this character is lost 

 in the adult Syndictyon. The bell in one of our examples was 

 entirely free from nematocysts. Agassiz (2) indicates a similar 

 apical canal in his S. reticidattmi just freed from the polyp-nurse 

 (fig. 291, p. 178). ^ . . , ^ , 



The absence of gonads, the presence of this apical canal, and 

 the presence of urticating-organs on the exumbrellar surface ot 

 the bell indicate the immature condition of our examples. 

 Possibly they maybe the young of some other species ; it has 

 been placed under the species it resembles most. Syndictyon 

 angulatuvi was found by Mayer (27, p. 5) off Turks Islands m the 

 Bahamas. , 



DiPURENA MacOrady. 



1. DiPURENA DOLiCHOGASTER (Hacckel, 18, p. 25). 



SpedfiG description.— The beU is a low truncated cone, 2 mm. 

 high by 1-75 mm. broad in the region a little above the tentacles. 

 From this, its widest diameter, the bell draws rapidly inwards, 

 ending in a rounded cone-shaped top. The velum is narrow. 

 The four tentacles are small and rather spindle-shaped, and m the 

 contracted condition are surrounded by six or seven rings or 

 welts of urticating-organs. The end-rings cause the appearance 

 of bulbs at the base of the tentacles. 



The tentacle-bulbs are very large in proportion (1-5 by 1-25 mm.) 

 to the other organs, somewhat crescent-shaped, seated m a 

 curved depression on the bell-margin. On the outer end of 

 each bulb there is an eye-spot. 



The digestive cavity is a large cylindrical tube hanging down a 



