98 THE MEDUSAE. 



than in other species of Pegantha which I have examined. It is possible, 

 however, that this feature may be due to the rather unsatisfactory condition 

 of the specimens. The marginal lappets are about as broad as long, and 

 somewhat pentagonal in outline (PI. 20, fig. 5), though less so than Maas 

 has figured them for P. dactgletra ('93, taf. 5, figs. 1, 2). The incisions 

 between the lappets are shallow and the peroniae correspondingly long. 



Tentacles. — The greatest number of tentacles and lappets is twenty-two, 

 in the largest specimen, while the only other individual with gonads has 

 nineteen. The number, though variable, is thus considerably larger than 

 in either P. martagon or P. triloba. A specimen 30 mm. in diameter, which 

 as yet shows no trace of gonads, has only sixteen tentacles, one of them 

 evidently of much more recent formation than the others (PI. 20, fig. 4) ; 

 but since no trace of the sexual organs is yet visible in this specimen, it is 

 by no means certain that sixteen would have been the final number. The 

 tentacles are of the usual type ; about two thirds as long as the diameter 

 of the bell, and in life carried projecting stiffly (PL 16, fig. l). 



Otocysts. — There are usually seven otocysts per lappet in the larger speci- 

 mens ; but unfortunately the margins of both adult individuals were so 

 battered that I could count them in only a few lappets. The sense organs 

 themselves (PI. 20, fig. 6) are oval in outline, contain two or three otoliths, 

 and are situated on small ectodermic pads. The otoporpae are much shorter 

 than in other members of the genus which I have examined, extending hardly 

 across the ring canal (PI. 20, fig. 4; PI. 27, fig. l). 



Gastro-vascular system. — The stomach is flat. In young specimens, in 

 which its form is not obscured by the gonads, it is circular (PL 20, fig. J,). 

 The mouth is surrounded by a simple circular lip, in all the present speci- 

 men- widely opened. The canal system is well developed, both peronial and 

 ring canals being very broad. 



Gonads. — The gonads arc not definitely subdivided, but, as in P. martagon, 

 each consists of a single main swelling, which, in the present species, bears 

 a variable number of oval or papilliform processes (PI. 20, fig. 5). On com- 

 parison wit! M figure (' ( J3, taf. •">, fig. /) it will be seen that this type of 



id very closely resembles that of P. dactgletra, differing only in that the 

 like processes in /'. laevis arc smaller, — a difference of doubtful impor- 

 tance, -imv it is h\ no means certain that the gonads of any of the present 

 1 ave reached their maximum development. As in the three other 

 Pegantha de cribed in this paper, each gonad is supported by a 

 I I prominence of i In- gelal inous disc. 



