214 



THE MEDUSAE. 



by the "Albatross" in Behring Sea, at Station 3325, in 121 fathoms of 

 water. 



Size. — Both the specimens in the present collection are of about the 

 same dimensions, measuring about 30 mm. in height by 22 mm. in greatest 

 diameter. One is perfect; in the other the manubrium is torn away. 



The Behring Sea individual of about the same size is contracted, but is 

 further advanced, as is shown by the condition of the gonads. 



The bell is high, the gelatinous substance thick at the apex, but without 

 apical projection. As in S. geometrica (Maas : 05) the bell in all three speci- 

 mens is laterally flattened so that one diameter is much greater than the 

 other (PL 5, fig. 5). 



The manubrium is barrel-shaped ; readily separable into basal, gastric, 

 and labial portions (PL 43, fig. 1). It is about one third as long as the 

 bell cavity is deep. Its base is cruciform, an outline particularly pro- 

 nounced in the Behring Sea specimen (fig. 2), with its four arms passing 

 gradually into the four radial canals, as Maas has noted (: 05, p. 17). 



Canal system. — In the two younger specimens there are, in addition to 

 the four radial canals, eight adradial blind canals which extend centripetally 

 from the ring canal almost to the base of the manubrium. Their blind ter- 

 minations are clearly visible in the photograph of an oral view (PL 5, 

 fig. 5). Owing to the excellent condition of both specimens this important 

 feature could be demonstrated beyond question. The adradial, like the 



radial canals, have no diverticulae, 

 nor are they branched. However, 

 one of the blind canals showed an 

 irregularity in being connected with 

 the neighboring radial canal by a 

 transverse bridge. 



In the older specimen, from 

 Behring Sea, the condition of the 

 canals more nearly suggests that 

 described by Maas (: 05). In place 

 of ending blindly, the adradial canals now connect with the four arms of the 

 cruciform basis of the manubrium i fig. .'). They have increased in number to 

 twelve and arc somewhat irregularly arranged. None of them are branched. 

 When taken In connection with the conditions in the younger specimens in 

 which the adradial canals end blindly, it is evident that the adult state results 



Fig. 2. 



