EEPORT ON THE HYDKOIDA. 39 



Aglaoplienia calamus, n. sp. (PL XII. figs. 5-8). 



Tropliosome. — Golouy attaiuiiig a height of aljuut five inches ; stem mouosiphouic, 

 simple, or with a few branches springing from its anterior aspect ; hydrocladia rather 

 close, about two-tenths of an inch in length. Hydi'othecae with the margin deeply 

 serrated ; intrathecal ridge short, near the floor of the hydrotheca ; mesial nematophore 

 adnate to the walls of the hydrotheca for aljout half their height, and then continued as a 

 short spur-like process, which does not reach the level of the hydrotheca margin ; lateral 

 nematophores somewhat fiask-shaped, slightly overtopping the margin. 



Gonosome.— Covhula rather long, cylindrical, with about seven pau-s of adnate costse, 

 each costa carrying four or five tubular denticles, and with a spur-like denticle at its base. 



Aglaophenia calamus shows no divergence from tlie typical Aglaophenia;. It is a 

 species with rather close-set hydrocladia, and with a tendency to send ofi" short branches 

 from the anterior side of the plume. 



Dredged off" Bahia, from a depth of 10 to 20 fathoms. 



Aglaophenia coarctata, n. sp. (PL XIX. figs. 7-9). 



Trophosome. — Hydrophyton attaining a height of upwards of six inches ; stem 

 fascicled, sending oft' alternate rather distant branches, along which the hydi'ocladia are 

 disposed in alternate pinnae, which scarcely attain a length of two-tenths of an inch. 

 Hydrothecse closely approximated, deep, with the margin crenate, and with a prominent 

 tooth in front ; mesial nematophore strong, adnate to the hydrotheca walls for about two- 

 thu'dsof the height of the walls, and thence continued as a short free process, which does 

 not reach the level of the hydrotheca margin, and with a wide emarginate orifice; lateral 

 nematophores thick, tubular, not overtopping the hydrotheca. 



Gonosome not known. 



The hydrothec8B of the present species are so closely approximated that the lower end 

 of each is included in the orifice of that which lies at its proximal end. They are 

 unusually deep, and the margin, instead of presenting the ordinary dentate condition, is 

 merely crenate, with an anterior mesial point in the form of a sharp tooth. The Ijranches 

 which support the hydrocladia are divided by oblique joints into a series of wedge- 

 shaped internodes, each internode sending off" a single hydrocladium. The main stem is 

 strongly fascicled, and the nature of the communication between its component tubes 

 may be easily seen. These communicate with one another by very short lateral offsets, 

 each tube emitting numerous such offsets, whose ends meet those of corresj)onding offsets 

 from the neighbouring tubes (fig. 1, p. 5). 



No part of the gonosome was present in the specimen, and there is perhaps no better 

 reason for assigning it to Aglaophenia than to other genera of Statoplean Plumularidce, 



