MAYER; MEDUSA FROM THE WESTERN ATLANTIC. 3 



and project slightly beyond the mouth opening. The stomach is large, its 

 diameter being about ^ that of the umbrella itself. Sixteen wide, simple 

 radial pouches extend outward from the stomach cavity into the peripheral 

 regions of the umbrella. Eight of these pouches go to the marginal sense- 

 organs, and 8 to the tentacles which are hollow throughout almost their 

 entire length. There are 8 radial bands of muscle fibres in the ex-umbrella. 

 These go to the marginal sense-organs. The gelatinous substance of the disk 

 is translucent but slightly bluish in color. The clusters of nematocysts over 

 the aboral surface are dull yellowish brown, and the tentacles are slightly 

 green in color. 



Single specimen, Narragansett Bay, Rhode Island. 



HYDROMEDUS^. 

 STOMOTOCA, L. Agassiz, 1862. 

 Stomotoca apicata, L. Agassiz. 



Fig. 3 cf, Fig, 4 9, Plate !J. 



■ Saphenia apicata, McCrady, J., 1857, Gymn. Charleston Harbor, p. 27, 



PL VIII. Figs. 2, 3. 

 Stomotoca apicata, Agassiz, L., 1862, Cont. Nat. Hist. U. S., Vol. IV. 



p. 347. 

 Stomotoca apicata, Agassiz, A., 1865, North Amer. Acal., p. 168. 



iDinematella cavosa, Fewkes, J. W., 1881, Bull. Mus. Comp. ZoiJl. Har- 

 vard Coll., Vol. VIII. p. 151, PI. II. Figs. 2, 3 ; PI. IV. Fig. .S. 

 Dinematella cavosa, Fewkes, J. W., 1884, Amer. Nat., Vol. XIX. p. 195, 

 I- Fig. 



Stomotoca apicata, L. Agassiz, is distinguished by the fact that the entoderm 

 of the proboscis in the male is emerald green, or straw-colored ; and in the 

 female dull ochre. ALso the tentacle bulbs in the male are purple, and in the 

 female dull ochre. This species has been confounded by Brooks, 1883, and 

 Fewkes, I88I, with another form in which the entoderm of the proboscis and 

 tentacle bulbs is brick-red in both sexes. For this brick-red form we propose 

 the name Stomotoca rugosa. 



Specific Characters. — Stomotoca apicata. In the adult medusa the bell is 

 about 4 mm. high and 2 mm. broad. It is provided with a prominent 

 apical projection that is solid in the males, but usually hollow in the females, 

 the gastro-vascular space leading upward into it. There are two long tentacles 

 with large, hollow basal bulbs. In addition to the two long tentacles there are 

 usually 6 small rudimentary tentacle bulbs upon the bell margin. The pro- 

 boscis is flask-.shaped, there is no peduncle, and the 4 lips are curved slightly 

 upward. The ectoderm of the upper portion of the proboscis, under the 4 

 radial tubes, is thrown into folds or convolutions, and it is in this region that 



Male 



Female 



