SO AMERICAN HYDUOIDS. 



SCHIZOTRICHA TENELLA (Verrill). 

 (Plate IV, ligs. 4,5.) 



riumularia tenella VKHRII.I,, Invertebrate Animals of Vineyard Sound, 1874, p. 731. 

 riumularia Irni-Un CLARK, Trans. Conn. Acail. Sci., 1875, III, p. 65. 



Trophosome.* Colony branched dichotomously, attaining a. height of 1! inches and growing in 

 clusters; stein divided into alternate longer and shorter internodes, the latter bearing each a 

 hydrotheca and a hydrocladhun; hydrocladia often branched alternate, very slender, not very 

 long, proximal internode short and without hydrotheca, the rest of the hydrocladium being com- 

 posed of three kinds of internodes, every third one being stouter and liydrothecate; next there is 

 a very short internode followed by a long, slender iuternode live or six times as long as broad, 

 articulated by an oblique node at its distal end with a liydrothecate internode, making two, a, 

 short and a long, intermediate iuternodes between adjacent hy.lrotheca 1 . Hydrotheca- subcylin- 

 drical, a little longer than broad, having the distal half free; lateral nematophores present; a 

 mesial uematophore at the base of each hydrotheca, one or two on the long intermediate internode; 

 cauliue neuiatophores one or two to each intermediate internode. 



GonoKome. Gonangia in the shape of curved cornucopia', slender at the base and gradually 

 enlarged to the end, and with three or four neuiatophores at its base. 



Distribution. Otf Gay Head, S to 10 fathoms; Vineyard Sound, 8 fathoms; New Haven, 

 Connecticut; Greenport, Long Island. 2 Abundant on the piles of the U. S. Fish Commission 

 dock at Woods Hole, and also on the piles of the dock at Vineyard Haven. 3 



The branched hydrocladia may be, as elsewhere suggested, a character which is gonosotual in 

 its nature, but it throws the species into the genus Schizotricha. 



Type. In Museum of Yale University. 



SCHIZOTRICHA GRACILLIMA (G. O. Sars). 

 (1'lato XIV, ligs. 4-6.) 



riumularia yrai-iUima O. O. SAKS, Hidraj; til Knndskaben oiu Dyrelivet paa vore Ilavlianker Chr. a Vid. Selsk. Forh. 



for 1872. 



riumularia verrillii CLARK, Trans. Conn. Acad., 187">, III, p. 64, pi. x. 



Plitmnlaria rerrillii VKRRILL, I'reliin. Check-list Marine Invert, of Atlantic ('oast, etc., 1879, p. 18. 

 Plitmnlaria I'errillii KKWKES, Bull. Essex lust., 1891, XXIII. Xos. 1-3, p. 39. 



Hydrocaulus sparingly branched, and attaining a height of '2.\ inches; mam 

 stem and branches fascicled, the latter, however, soon becoming simple, divided into regular 

 interuodes, each of which supports a hydrocladium on a stout process from near its distal emi: 

 hydrocladia. alternate, usually branched dichotomously one, two, or three times, beyond its proxi- 

 mal internode, and divided into regular, long, slender iuternodes, each of which bears a hydrotheca 

 on its distal half; there is an occasional short intermediate internode. Hydrotheca- small, cup- 

 shaped, about as wide as deep; uematophores large, bithalamic; a supracalyciue pair, and three 

 or four single mesial ones to each regular internode, or between adjacent hydro thecse; a cauliue 

 nematophore in the axil of each hydrocladium, and others scattered irregularly over the stem. 



Oonosome. Gonangia borne in pairs on the stem near the axils of the hydrocladia, and also 

 at the forkiugs of the latter. They are cylindrical in shape, tapering at the proximal end and almost 

 sessile, the pedicel being much reduced. Length about two and one-half times the greatest 

 diameter. The younger gonangia are much shorter and inclined to be triangular in outline when 

 viewed from the flattened side. 



1 Description of specimens from the Museum of Yale University kindly loaned by Professor A. E. Verrill. 



-Clark, Transactions of the Connecticut Academy of Sciences, III, p. (>5. 



'Since writing the above I have seen Hincks's description and figures of I'lumularia cornucopia" in Annals and 

 Magazine of Natural History, November, 1872. and suspect that it may be the same as Sclii:otriclia tenella. In the 

 absence of specimens for comparison, however, it seems best to regard them as separate. 



