REPORT ON THE HYDROIDA. 41 
Lytocarpus racemiferus, n. sp. (Pl. XH). 
Trophosome.—Colony attaining the height of about twelve inches ; stem fascicled, 
much and irregularly branched, main branches all directed towards one side of the stem ; 
hydrocladia alternate, scarcely exceeding one-tenth of an inch in length. Hydrothecz 
rather deep, margin serrated, teeth blunt ; intrathecal ridge well marked, situated near 
the fundus of the hydrotheca; mesial nematophore adnate to the walls of the 
hydrotheca for nearly their entire height, and then continued as a short, blunt beak, 
which scarcely overtops the hydrotheca and has both a terminal and a lateral orifice ; 
lateral nematophores slightly overtopping the hydrotheca. 
Gonosome.—Phylactocarps in the form of long racemes, laden with gonangia, spring- 
ing from certain branches of the trophosome at points near the origin of the branches 
from the stem, and there taking the places of the proximal four or six hydrocladia, con- 
sisting of a series of internodes having every internode provided with one median and two 
lateral spines, each of the proximal five to eight internodes carrying also an ovate pedun- 
culated gonangium. 
Lytocarpus racemiferus is an exceedingly beautiful species. The direction of the 
principal branches from one side only of the main stem give it a habit not usual among 
the Plumularide. The phylactocarps, with their pedunculated gonangia, form elegant 
racemes, grouped near the proximal ends of the branches, where they replace the 
hydrocladia of this part of the branch. Towards its distal end the branch carries the 
ordinary unmodified hydrocladia, which are continued to its extremity. 
The phylactocarps are, in the present species, of much morphological significance, and 
must be viewed as hydrocladia modified by the suppression of the hydrothece, whose 
places are taken towards the proximal end of the phylactocarp by the gonangia, and 
whose mesial and lateral nematophores have undergone but little change, and are 
represented by the three spines carried by each internode. These spines retain their 
essential character as nematophores, and are each provided with a terminal oblique 
orifice. Several of the more distal internodes are destitute of gonangia and carry only 
the spines. 
The gonangia are supported on rather long peduncles, which spring from between 
the bases of the two lateral spines, and are subtended by the mesial spine. The 
gonophore occupies the centre of the gonangium, from whose walls it is separated by a 
clear space, across which may be seen a wreath of highly refringent spherules, by which 
the summit of the gonophore is encircled. The sex could not be determined with 
certainty. 
Dredged off Bahia. Depth 10-20 fathoms. 
(zooL, CHALL. EXP.—PART xx.—1883.) U6 
