b BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



in the female the ova are large and promiuent. The proboscis is pearl- 

 colored, or of a delicate green. The entodermal cores of the tentacle bulbs 

 are red surrounded by a delicate yellow-green. The supporting lamella of 

 the bell often displays a faint greenish tinge. 



Young Medusa. — In the young medusa there are but 8 tentacles, 2 from 

 each tentacle bulb. The bell is a little higher than a hemisphere and the 

 gelatinous substance is not very thick, being of about uniform thickness every- 

 where instead of being very thick at the aboral pole, as in the adult. The 

 proboscis is short and quadratic, and there are 4 short, unbranched, knob- 

 shaped oral tentacles. When the medusa is about 3 nmi. in height, the 

 bell is still hemispherical. The proboscis is wide, shallow, and quadratic, 

 and the oral tentacles branch once dichotomously. About 4-5 marginal 

 tentacles arise from each tentacle bulb. 



This medusa is found in Newport Harbor, Ehode Island, from July until 

 October. 



This species is distinguished from Margelic carolinensis, L. Agassiz, by the 

 greater height and less width of its bell. Also in M. carolinensis the pro- 

 boscis is long and slender, while in B. Gibbsi it is short, wide, and cruciform 

 in cross-section. The proboscis of M. cai'olinensis is widest at about the 

 middle point of its length, while that of B. Gibbsi is widest at its proxi- 

 mal base. 



LYMNOREA, Pekon and Lesueoe, 1809. 

 Lymnorea borealis, nov. sp. 



Figs. 16-18, Plates. 



Specific characters. — The bell is 3 mm. in height. The bell walls are thin, 

 and there is a slight apical projection. There are 32 well-developed marginal 

 tentacles with large basal bulbs. These tentacles are about \ as long as the bell 

 height, and are curled slightly upward. They are not very flexible. The 

 velum is well developed. There are 4 straight, narrow radial tubes. The 

 proboscis is pyriform and the mouth is surrounded by 4 short, dichotomously 

 branching, oral tentacles. Each of these oral tentacles branches 2 times, thus 

 giving rise to 4 tentacle tips (see Figure 18). These tips are short and 

 knob-like and are covered with long slender nematocyst capsules borne upon 

 thread-like filaments (see Figure 17). The gonads occupy 4 radially situated, 

 longitudinal swellings upon the proboscis. The entoderm of the proboscis, 

 and of the bulbs of the marginal tentacles, is red. 



Three specimens, all of them being males, were found in Eastport Harbor, 

 Maine, on September 19, 1898. 



