52 EDWARD T. 15K0WNB. 



Family ULMARID^E.* 



DiPLULMARis, Maas, 1908. 



Qt-nevic Characti'r. — Ulmaridae witli IG rhopalia, IG tentacles, and 32 marginal 

 lobes, regularly alternating (with numerous radial canals, some branching and all 

 anastomosing in a network at the periphery and communicating with a circular 

 canal). 



DirLri,MARIS ANTARCncA. 



(Plate VI.) 



DipMmaris atUarctica, Maas, 1908, p. 9, PI. II., fips. 2, 3. 

 Uhnaropsis dri/i/ahkii, VanliofTeii, 1908, p. iH, figs. l(i-12. 

 Ulmaropsis antarr/ira, Vaiilioffen, 1909, Deutsche Siidiwliir Exped. Vorwort. Bd. x. (Zool., Bd. ii.), p. v. 



This interesting Medu.sa was first described by Maas as a new genus and species, 

 and his description is based upon two specimens collected by the French Antarctic 

 expedition. A few months after the appearance of Maa.s' report on the Medu.sa) of the 

 French expedition, Yanhoffen's report on the Medusae of the German Antarctic 

 expedition was published, and in it he described a new Medusa under the name of 

 Uhnaropsis dryyalskii, n.g. et n.sp. Messrs. Maas and Vanhoffen soon recognised 

 that both expeditious had collected specinions of this new Antarctic Medusa, and that 

 they had descril)ed it under different names. This was, lu^wcver, unavoiilable, owing 

 to the short interval of time between the publications of the two reports. 

 Dr. Vanhoffen (1909) recognises Maas' priority and proposes that the name UliiKiropsis 

 antarctica should be used instead of rh'j/lulinari" iintitrct'ic/t. I am .sorry that I cannot 

 agree to Vaiihoeffen's proposed generic name, because it is directly oppo.sed to the 

 rules of nomenclature, which are very clear and definite on this point. The generic 

 name Diphdmaris has priority over Ulmaropsis, just as the .specific name antarctica 

 has priority over dri/r/als^ii. The name PIpInlmaris is quite valid and must be u.sed. 



The ' Discovery ' brouglit home twenty-six specimens of this species, and they 

 nearly all belong to the epliyra and meta-ephyra stages; but three are certainly 

 adults. 



There is also a single specimen in the 'Sduthern C'ro.ss ' collection. It belongs to 

 the meta-ephyra stage, and was taken at Cape Adare on 10th ^lay, 1899. 



Tlie Ephijra staye (Plate VI., fig.s. I and 2). — The smallest and youngest specimens 

 of the series are between 4 and 5 mm. in diameter, and have the typical ejjhyra 

 appearance. .\t this stage the ephyra Las sixteen fairly long arms, eaili diviiled into 

 two Hat lobes, which in the adult become the marginal lobes of tlie umbrella, and each 

 arm carries a rhopalium. There are thirty-two straight, unbranched, radial canals, 

 sixt,cen of which run direct from the stomach to the rhopalia, and sixteen belong to 



* As UlmarU in a name coined by Prof. Hoeckcl, and not of Greek origin, Uliiiarida- may be allowed to pass, 

 but Diplulmaru is so shocking a hybrid that a protest must be entered. UlmaroptU is, of course, as bad. — Ed. 



