26 University of CaMfornia Publications in Zoology. [Vol. 6 



Diego, in June and July. Ace. Nos. 77 (type). 902, 959. 966, 

 1246, 1379, 1391, 1393, 1398, 1402. 



Among 90 individuals, only 10 possessed cirri. In three of 

 these (Ace. No. 77), the cirri are as described, in excellent con- 

 dition. In the remaining' seven (Ace. Nos. 1246, 1379) a few 



scattered stumps and nidi ats are to be found. The 80 non- 



cirrate individuals are of all sizes and conditions of preservation. 

 Assuming the eirrate form to be typical, it would appear that 

 the absence of cirri may be due (1) to accidents of environment 

 and (2) to spontaneous variation. The eirrate and non-cirrate 

 forms might perhaps be regarded as distinct species — even gen- 

 era, were the frequent practice of authors to be followed. Ilarl- 

 laub (1897) distinguished Eutonina from Eutimal plies on essen- 

 tially this basis, though he also considered the size of the stomach. 

 For the present, however, this does not seem to me to be the 

 wisest course to adopt with the San Diego material, as careful 

 comparisons of eirrate and non-cirrate individuals has failed to 

 reveal any other difference, even in the smallest details. Fur- 

 ther, in the typically eirrate Mitrocoma discoidea, there is a large 

 range of variation in the number of cirri. 



The gonads arise as linear bodies along the radial canals, 

 each with one end resting on the base of the gastric peduncle, 

 the other half-way to the margin. The growth is therefore cen- 

 trifugal. 



Gen. Irene Eschscholtz, 1829. 



Eueopidae with numerous tentacles, statocysts and mar- 

 ginal cirri ; gastric peduncle short ; gonads not occupying the 

 entire length of the radial canals. 



The following species has been placed here provisionally only, 

 since the presence of cirri has not been demonstrated. In all 

 other respects, however, it is a typical Irene, and there is a 

 strong probability that the cirri may have once been present 

 (cf. Mitrocoma discoidea and Eutimalphes brownei). 



Irene mollis, n. sp. 



Fig. 11. 

 Umbrella about twice as broad as high, jelly thin and soft, 

 gastric peduncle moderate. Manubrium short, with thin walls 



