HYDROMEDUSAE, SIPHONOPHORES, AND CTENOPHORES. 297 



paper on the Eastern Pacific Medusae (1909a) I followed Maas, de- 

 fining Eutima as " Eucopidae with long peduncle ; with only eight 

 otocysts; with only a small number of tentacles (4, 8, or 12) ; gonads 

 on subumbrella, on peduncle, or on both." But the present collec- 

 tion shows -that we can not limit the genus to specimens with 12 

 tentacles or less because to do so would make certain individuals 

 of levuka fall into one genus, others into another. And inasmuch 

 as number of tentacles, being an intergrading character, is seldom 

 a satisfactory limit to Hydromedusan genera, it is wiser to follow 

 Mayer (1910) and to include in Eutima all eucopids with long 

 peduncle, eight otocysts, and with marginal warts and cirri as well 

 as tentacles, as opposed to Eutimium in which there are neither warts 

 nor cirri. 



As pointed out below, the characters on which Hartlaub sub- 

 divides the genus Eutima (that is, number and arrangement of mar- 

 ginal organs and extent of gonads on radial canals) are very variable, 

 the latter, at least, almost worthless even as a specific character. To 

 use them as generic limits would throw some individuals of a given 

 species into one genus, others into another. 



The numerous described "species" of Eutima (Mayer 1910, lists 

 12, not counting synonyms) have recently been revised by Vanhoffen 

 (1912), who reduces the number to 3, as follows: With 4 tentacles 

 only, E. mira McCrady; with 8 or more tentacles and peduncular 

 gonads limited to the mid-region of peduncle, gegenbauri Haeckel ; 8 

 or more tentacles, with peduncular gonads (if present) long, E. gen- 

 tiana Haeckel. Considering how very variable, in all characters, the 

 genus Eutima is, this reduction is warranted, in the main, and it is 

 a question whether there is any real distinction between gegenbauri 

 and gentiana. 



The following Eutimas have been recorded from the Indo-Pacific : 

 levuka Agassiz and Mayer, lactea Bigelow, curva Browne, orientalis 

 (Browne), gentiana Haeckel as recorded by Vanhoffen, australis 

 Mayer (1915), orientalis Hartlaub, and modesta Hartlaub. Levuka, 

 lactea, and Hartlaub's orientalis are undoubtedly a single species, the 

 chief difference between them are the cirri, whether flanking the 

 tentacles, or the rudimentary knobs, or both; thus levuka has cirri 

 flanking the knobs alone (Maas 1909) or both knobs and tenta- 

 cles (Bigelow 1909a) ; lactea has them in connection with the ten- 

 tacles but not the knobs, and in adult orientalis there are none 

 (Hartlaub 1909, p. 457). But two specimens in the present collec- 

 tion show that the arrangement of cirri is not a sound character for 

 diagnosis, because in a given quadrant some of the knobs have them, 

 while others lack them, and the same, as described more fully below. 

 is true of the tentacles. And it has long been known that cirri are 

 veiy variable in their occurrence in the Atlantic E. mira, even more 



