84 AMERICAN HYDROIDS. 



arise; stein, branches, and branclilets polysyphonic, tlie latter bearing on the anterior surface 

 of each a tube from which the hydrocladia arise; proximal hydrocladia unbranched, the distal 

 hydrocladia biramons; the uubrauched hydrocladia and the posterior rain us of the others divided 

 into regular internodes, each of which bears a hydrotheca; the anterior ramns of the forked 

 hydrocladia bears a hydrotheca at its base and a few toward the distal end, where they become 

 about as closely approximated as in the other branches. Hydrotheca} distant, rather shallow, 

 cup-shaped; nematophores large in si/.e and excessively developed in numbers, especially on the 

 distal portions of the hydrocladia, there being in addition to the usual supraealycinc pair some- 

 times as many as live mesial nematophores to a single internode; cauline nematophores very 

 numerous, there being a row on both sides of the hydrocladia-beariug tube and a number scattered 

 over the rest of the stem. 



(fimoxomc. Gonaugia ovate, sac shaped, found usually on the stem and branches, but some- 

 times at the bifurcation of the hydrocladia. 



Distribution. Albatross Station L'liGli, lat. N. 3D ' -IS', long. \V. 7!P 111'; depth, U70 fathoms. 



This species is especially notable from the size and number of the nematophores. It also 

 goes far to demonstrate the theory advanced by the author that the forking of the hydrocladia is 

 merely a temporary contrivance connected with the maturing of the gonosome. If only the lower 

 portion of the hydrocladia bearing branches were examined, any naturalist would, without 

 hesitation, suppose that he had a species of I'luniulurm to deal with. 



Type slides. Cat. Nos. 18587, 18588, U.S.N.M; Cat. Nos. 11701, 117(12, Mus. State Univ. Iowa; 

 also iu the collection of the author. 



HIPPURELLA Allman (modified by Fewkesi. 

 Iliffinrellii Ai. I.MAN, Mem. Mils. Comp. Xool., 1877, V, No. 2, ]). 85; Bull. Mils. Comp. /<>ol., l.xsl, VIII, No. 7, p. 134. 



Trophosome. Colony branched; hydrocladia pinnate on the proximal portion of the stem, but 

 scattered on distal portion. 



Gonosome. Gonangia borne on distal portions of the branches, where the hydrocladia become 

 modified into protective nematophorous brandies, assume a verticillate arrangement, and 

 inclose the gonangia in a sort of pseudo-corbula; the protective branclilets bear each a row of 

 nematophores, but no hydrotheca 1 . 



Doctor Fewkes thinks that Professor Allman is mistaken in his original description in 

 speaking of the distal branchlets as if they were hydrocladia. Specimens before me, however, 

 have this structure, and for reasons mentioned presently I am of the opinion that Doctor Fewkes 

 was mistaken in his identification of the supposed Hippitrellit- tiniiiildtn collected by the Blake, and 

 had before him iu reality an altogether different species, which I will call HipjuircUn loni/iciirpn. The 

 genus, therefore, has the trophosome described by Allman, together with the gonosouie described 

 by Fewkes. 



HIPPURELLA LONGICARPA Nutting. 



(Plato XVII, ligs. 1-3.) 

 /lijifnirella iinniihiln FK\VKES (nut ALLMAX), Bull. Mus. Comp. X.ool., issi, VIII, No. 7, p. 134. 



Trophosome.* Colony attaining a height of nine inches, unbranched throughout the proximal 

 two-thirds, bearing alternate and subopposite branches on the distal third; stem fascicled, the 

 hydrocladia-bearing tube being surrounded by the accessory tubes; hydrocladia alternate, spring- 

 ing from opposite sides of the branches, divided into long iuteruodes, each of which bears a 

 hydrotheca, although an intermediate interuode is occasionally seen; internodes with several, 

 seven or eight, strong septal ridges, two or three of which are behind the hydrotheca. Hydro, 

 theca' separated by one and one-half times their height, deep, gradually widening toward the top; 

 aperture horizontal, anterior profile straight; supracalycine nematophores inserted near the top of 

 the hydrotheca'; a mesial nematophore borne on a protuberance below the hydrotheca and another 

 midway between adjacent hydrotheca': cauline neiiiatopliores numerous, arranged in regular 

 vertical rows upon the stem and branches. 



'Described from the specimen referred to Hifpurclla anniilala Alluniu liy Fewkes in his report on the Hlake 

 Hydroids. 



