belonging to the Family Laodiceidse. 405 



the other four adradial positions. The umbrella is nearly as 

 broad as high, about 1 mm., and has a few nematocysts 

 scattered over the exumbrella. The four perradial tentacular 

 bulbs have black ocelli on tlieir inner side. The medusa on 

 liberation is vv^ithout cordyli. 



MetschnikofF figures two specimens of the young hydroid, 

 one with a short hydrotheca and the other with a long hydro- 

 theca ; both are without transverse rings, which are generally 

 considered to be lines of growth. Miss Delap^s tigure is 

 similar to Metschnikoff's hydroid with a short hydrotheca, 

 but shows the transverse rings. 



The comparison of Cuspidella costata with Lafoea calcarata 

 of Agassiz shows that the two hydroids are not of the same 

 genus. The hydrotheca of Lafoea calcarata is without an 

 operculum, and its gonotlieca is also without an operculum 

 and is quite different in shape. Agassiz's hydroid is not a 

 Cufipidella, and it is not a true Lafoea, because it liberates 

 medusae. Lafoea has a peculiar gonosome, which until 

 recently was regarded as a distinct hydroid, geuerically known 

 as Coppinia. Moreover, the meduste liberated from these 

 two hydroids are not similar. Agassiz's medusa has two 

 tentacles and six tentacular buds, all with ocelli, and no cirri. 

 Miss Delap's medusa has two tentacles and two tentacular 

 buds, all with ocelli, and four cirri. Either Agassiz's hydroid 

 does not belong to Laodice calcarata, or if it does, then the 

 adult medusEe found on the American coast and on the British 

 coast should show specific differences, sufficiently conspicuous 

 to distinguish one from the other. 



I have in my collection of British medusae some young 

 stages of Laodice taken in tow-nets at Valencia in 1897 and 

 at the vScilly Isles in 1899 and 1903. The earliest stage, 

 about 1*25 mm. in diameter, has four perradial tentacles, each 

 with a black ocellus on the basal bulb, four interradial, eight 

 adradial, and a few scattered buds or bulbs, all without 

 ocelli. Between every two bulbs there is generally a cirrus ; 

 but there is not the slightest trace of a cordylus. As develop- 

 ment proceeds tentacles sprout out from the bulbs, more buds 

 or bulbs appear, and more cirri come into existence. It is 

 not until the umbrella is 3-4 mm. in diameter that cordyli 

 are clearly recognizable. (Many of the early stages were 

 examined alive.) 



Laodice is the only medusa on the British coasts with 

 black ocelli on the inner side of the basal bulbs and with 

 cirri, so that these early stages, without cordyli, are not likely 

 to belong to another genus. The presence of black ocelli and 

 cirri in the medusa liberated from Cuspidella costata indicates 



