NO. 1931. NEW MEDVSM FROM THE PHILIPPINES— BIGELOW. 259 



tentacle tips thus agree with those of Gossea, and more closely with the 

 secondary than with the primary tentacles of Olindias, though the 

 tentacles themselves arc homologues of the latter. All the other 

 tentacles arc broken short olF, except two of the radials, which have 

 apparently suffered the same fate, but regenerated at the tips. On 

 the young tentacle no terminal annulatious or knobs have developed 

 yet. The tentacles arise from the margin, but curs^e upward against 

 the bell, where they lie in furrows of the exumbrella. A slight dis- 

 tance above the margin they bend outward, away from the bell. 

 This is a condition very much like what we find in Heterotiara. In 

 Olindias, and especially in Olindioides, the basal parts of the ten- 

 tacles have become entirely inclosed by the gelatinous substance, so 

 that these organs actually do emerge from the exumbrella, but in 

 Nauarchus the furrows remain open permanently. 



Otocysts. — There is a single otocyst close beside each tentacle, lying 

 within the exumbrella furrow, which sheaths the tentacle, but stand- 

 ing free instead of being inclosed in the gelatinous substance. The 

 sense organ itself is a naked club, much like the corresponding organ 

 in Amphogona, or Aglantha, except that it is nearly spherical. The 

 covering layer of ectoderm can easily be distinguished from the ento- 

 dermic core. In the only otocyst which was in perfect condition, or 

 which I could study, this entodei-m C(U'e consists of four large spherical, 

 somewhat flattened, cells, each containing a small central mass which, 

 judging from its high index of refraction, is the calcareous concretion. 



Color. — All three specimens are colorless, at least after preservation, 

 and very transparent. 



The above description, taken from the t37pe, applies very well to 

 one of the other specimens also. But the remaining one is abnormal, 

 so far as gonads and radial canals is concerned. Three of the canals, 

 with their gonads, are of the normal type, but the other three are rep- 

 resented by a single trunk leaving the margin of the manubrium. 

 This soon divides into three, each of which bears a gonad , leaflike in 

 form but of rather less than normal size. Two of the resultant canals 

 run to the margin, but the third ends with the end of the sexual gland. 

 The specimen has 13 tentacles, two interradials in one sextant, one of 

 them A^ery small. Such an aberrant specimen is less surprising in this 

 genus than it would be in some other families, for even more remark- 

 able examples have been recorded for Gonionemus. Canals, gonads, 

 and manubrium all vary to an extraordinary degree in these genera. 



The foregoing account shows that this new genus does not fit in 

 very well either with Mayer's * definition of Olindiidee as having, 

 Petasinae hs lacking, sucking disks on the tentacles, for though the 

 structure of the margin shows unquestionable affinity with such 

 genera as Gonionemus and Olindias the terminal knobs on the tentacles 



> Medusae of the World, vol. 2, igiQ. 



