952 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [26] 



AGLAUEA. VITREA, Fewkes. 



Aglanra is common along the Florida Keys, and occurs in the latitude 

 of the Bermudas. 



NARCOMEDUSiE, Haeckel, 1877. 



HALIOEEASID^, fam. nov. 



Haliceeas, FewkeSj 1882. 



(Plate VIII.) 



There are several specimens of this most extraordinary genus, some 

 of which are well preserved, from which I am able to add something to 

 what little is at present known of its anatomy. In 1882 {Bull. JItis. 

 Comp. Zool., vol. ix, Xo. 8), from two specimens collected by the U. S. 

 Fish Commission, I established a new genus and species, to which 

 was then given the name of Halicreas minimum. This medusa reoccurs 

 in the collections of 1883, and from them the fragmentary observations 

 then made can now be confirmed and several others added to our limited 

 knowledge of its exceptional anatomy. 



Halicreas is recognized by the possession of eight rounded protuber- 

 ances {mg. p.), in many alcoholic specimens bearing rounded tubercles 

 of brownish color, placed on the margins of the disk. From these, 

 tubercles extend radially on the subumbra side towards the center of 

 the disk, like s})okes from the rim of a wheel, a corresponding number 

 of radial ribs, which are in some specimens well marked, in others less 

 evident. When seen on the siibumbral side in one specimen these 

 spokes (Figs. 1, 2, g.) seem to be glandular. Xo tentacles in alcoholic 

 specimens, and no proboscis. Eight sausage-shaped or tentacular- 

 formed bodies were observed in one specimen hanging down from the 

 under-side of the umbrella, each arising from a point between the ra- 

 dial ribs not far from the center of the disk. A line passing through 

 the center of the disk and the center of the point of attachment of 

 these structures cuts the margin of the umbrella midway between two 

 bundles of tubercles. 



The affinities of Halicreas with known genera are probably the nearest 

 to the strange family of Pectyllidte, Hasckel, and of these it has a distant 

 likeness to the genus Fectanthis in some particulars. In PectantJiis, 

 however, we have on the bell margin sixteen clusters of small tentacles 

 with sucker extremities, while in Halicreas there are only eight margi- 

 nal tubercles. Moreover, the surface of these tubercles is sometimes 

 covered with small conical teeth, which may in a distant way corre- 

 spond to the sucker-bearing tentacles of Fectanthis. These tubercles in 

 Halicreas never bear tentacles nor suckers. There are eight ovaries in 

 Halicreas^ and the genus has a very tliick velum, which is highly mus- 

 cular and contractile. This velum at times almost completely closes 

 the entrance into the bell cavitv. 



