NO. 2114. EPERETMVii, T\[EW OEWUS TRACH0MEDV8AE—BIGEL0W. 401 



Cubaia (VaUentinia'i) ; the structure of the tips of the tentacles from 

 Olindias and its close ally Olindioides. Its closest relative is appar- 

 ently the genus Maeotias of Ostroumoff . Unfortunately, the descrip- 

 tion and figures of the latter (Ostroumoff, 1896) are not as detailed 

 as could be wished, the structure of the tentacle tips being doubtful. 

 But, apart from this point, Maeotias, like Gonionemus, is characterized 

 by the presence of numerous marginal tentacular clubs, homologous 

 with the marginal (secondary) tentacles of Olindias and Olindioides, 

 structures entirely lacking in Eperetmus. And inasmuch as our 

 specimen of the latter is apparently sexually mature, we can not 

 suppose they would appear at a later stage. Another difference be- 

 tween Eperetmus and Maeotias, which may be equally important, is 

 that whereas the older tentacles of the former emerge from the bell 

 at a considerable height above the margin, the entodermal tentacular 

 roots of the latter are so short that the point of emergence of the ten- 

 tacles from the exumbrella is hardly appreciably above the margin. 

 Furthermore, the otocyst capsules offer another precise differentiation 

 between the two genera, being free in the latter, inclosed in the 

 jelly in the former. 



EPERETMUS TYPUS, new species. 

 Plate 59, figs. 1-8. 



Albatross Station 4754; Oct. 4, 1905; lat. 55° 03' N.; long. 131° 

 08' W.; about 2 miles off Mary Island, southern Alaska; one speci- 

 men, 15 mm. in diameter, in good condition: type; Cat. No. 36301, 

 U. S. National Museum. 



Fortunately the unique specimen is in good enough condition to 

 show aU its important anatomical characters. The beU is saucer- 

 shaped; in the preserved state (formalin) only about one-third as 

 high as broad; the exumbrella thickly studded with minute conical 

 prominences (fig. 2), which recall the surface roughness of Aurelia and 

 some other Scyphomedusae. The velum is broad and muscular as in 

 most related genera. The manubrium is cylindrical, hangs slightly 

 below the bell-opening, and is seated on a short, broad peduncle (fig.l, 4), 

 as in Gossea and in Olindias. The lip (fig. 1) is cruciform, crenulated. 

 and its margin thickly studded with spherical nematocyst knobs, 

 which, being of various sizes, are probably in constant process of 

 formation with the general growth of the Medusa (fig. 5). In all the 

 other members of the subfamily which I have studied, i. e., Gonione- 

 mus murbachii, G. vertens, and G. suvaensis, Gossea hrachymera, Cubaia 

 geopMla, Olindias singularis, 0. phosphorica, and Olindioides formosa, 

 the edge of the lip is smooth, though it may be folded. The radial, 

 circular, and centripetal canals are notably broad and flat. Of the 

 latter there are 4, 4, 4, and 5 in the respective quadrants, one inter- 

 81022°— Proc.N.M. vol.49— 15 26 



