60 THE MEDUSAE. 



The largest specimen measures 14 mm. in diameter and has twelve ten- 

 tacles. This appears to be the maximum number of tentacles, the majority 

 of specimens having from nine to eleven. The smallest specimens, 2 mm. 

 and 3 mm. in diameter, have only eight and nine respectively, and a specimen 

 5 mm. in diameter has nine; all the larger specimens have at least 

 that number, while a large specimen, 13 mm. in diameter, has only nine. It 

 appears, then, that in this species the adult number of tentacles is early 

 attained. 



The bell is rather high (PI. 1, fig. 6; PI. 15, fig. 1) and varies much in 

 outline according to the state of contraction of the specimen. The gelati- 

 nous disc is thick and higlily arched. The marginal lappets are short and 

 broad (PI. 1, fig. 6), the radial incisions separating them shallow, and the 

 peroniae short and covered over by the gelatinous substance of the adjacent 

 lappets. The surface of the bell is smooth, except for the ridges near the 

 margin which mark the course of the otoporpae. The tentacles are about as 

 long as the bell radius, and in life carried stiffly extended (PI. 15, fig. i). 

 Underlying the base of each tentacle, at its point of origin from the bell, is 

 an oval or kidney-shaped pad (PI. 28, fig. 4, np-)? consisting of crowded ectoderm 

 cells, among which are many nematocysts. These pads appear to afford 

 a good specific character, since they are constant in occurrence. 



The number of otocysts is variable, but in large specimens the number 

 in each marginal lappet is always much greater than three, the number 

 characteristic of C. globosa. The greatest number observed in any one lappet 

 was eight, the smallest, in a large specimen, four. The most usual number 

 is five or six. In the smallest specimen, 2 mm. in diameter, there were 

 three in some lappets, four in others. The otoporpae vary considerably in 

 length, but never extend over much more than half of the marginal lappets. 

 They are narrower than in C.glohosa, and of nearly uniform breadth through- 

 out their length (PI. 45, fig. 8). The sense organs themselves are rather 

 small, broadly oval in outline, and contain each a single large otolith (PI. 45, 

 fig. 6'). None of these organs were examined before preservation, and it is 

 probable that the rounded form of the otoliths is due to the corrosive action 

 of the formalin. In life many of the spindle-shaped cells of tlie "auditory 

 pads" bear bristles (PI. 45, fig. 8), but most of these are destroyed by 

 preservation. 



The central portion of the gastro-vascular system is of the usual Cunina 

 type, the stomach flat, the mouth surrounded by a simple circular lip, often 



