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Show 1903.J MEDUSAE 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 mouth 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) of S. reticidatum. N o gonads are to be distinguished. Colour.-Bell light brown, proboscis yellow, ocelli black. Habitat.-Victoria Harbour, collected by Shearer. Discussion.-The presence of urticating-organs on the exum-brellar surface of the bell (unless they are arranged in a definite manner retained in the adult stage) used as a generic character by Haeckel (18) is invalidated by the fact that these structures occur in many young Medusa?, e. g. Aurelia fiavidula, Dinematella cavosa (Fewkes), Proboscidactyla flavicirrata, Gonionemoides geo-j) hila, Polyorchis 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. reticidatum 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 of the bell indicate the immature condition of our examples. Possibly they may be the young of some other species; it has been placed under the species it resembles most. Syndictyon angulatum was found by Mayer (27, p. 5) off Turks Islands in the Bahamas. DIPURENA MacCrady. 1. DIPURENA DOLICHOGASTER (Haeckel, 18, p. 25). Specific description.-The bell is a low truncated cone, 2 m m. high by 1*75 m m . 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 in 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 P25 mm.) to the other organs, somewhat crescent-shaped, seated in 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 |