500 MR. JAMES RITCHIE ON HYDROIDS [^^7 28, 



II. CALYPTOBLASTEA. 



Family Haleciid^. 

 Halecium beanii Johnston 1838. 



Several strongly fascicled, irregularly branched colonies. The 

 delicate structure of the terminal branchlets is chai'acteristic of 

 the species. The branches differ from those in the specimen 

 figui'ed by Allman (1888, pi. xii. fig. 3 «) in arising laterally 

 fi'om below a hydrotheca, instead of directly from the branch. 

 The majority of the primary hydrothecss differ from Allman 's and 

 from Hincks's (1868) figures in being sessile and adnate to the 

 node from which they arise — the hydrotheca-tier springing from 

 within the primary hydrotheca ; but in these respects they agree 

 with specimens from the French coast described by Dr. A. Billard 

 (1904, p. 163), and with specimens from dredgings made by the 

 Scottish Antarctic Expedition at Burdwood Bank, near Cape 

 Horn (Ritchie, 1907). 



The bright refringent points which encircle the base of the 

 hydrotheca are in this species, as in others I have examined (1907, 

 p, 515), points of attachment for strands from a fleshy disc at the 

 base of the polyp, which is thus supported within its minute 

 hydrotheca. 



The gonosome is absent in the present specimens. 



Locality. St. Vincent, Cape Verde Islands, growing on the 

 bottom of a lighter ; 30th July, 1904. 



Ophiodes CACiNiFORMis, sp. n. (Plate XXIII. figs. 11 & 12; 

 Plate XXIV. fig. 1 ; Plate XXV. fig. 5.) 



Several small, delicate colonies, for which this species has 

 been formed, arise at irregular intervals from a hydrorhizal stolon 

 creeping upon a fragment of a sand- covered worm-tube. They 

 are neither branched nor fascicled, and the largest is but 6*5 mm. 

 in height. The stem is divided into short internodes, 0*4 mm. 

 long in the proximal, but gradually lengthening to 0"6 mm. in 

 the upper part of the colony. The distal end of each internode 

 appears to divide into two equal, slightly diverging portions, one 

 of which forms the peduncle of a hydrotheca, while the other bears 

 the succeeding internode, the junction between the two internodes 

 being marked by a single annulation. 



The hydrotheca^ lie in one plane, are placed one on each inter- 

 node, and are alternate. They are borne on peduncles of varying 

 length, from 0*05 to 0'2 mm., the upper portions of which are 

 delicate and freqiiently crumpled, while the bases are thick- walled 

 and, even when the hydrotheca itself has been destroyed, remain 

 as projecting processes. The hydrothecpe themselves are shallow, 

 trumpet-shaped cups, with much-everted margins, delicate walls, 

 and a thin septum separating their cavity from that of the stem. 

 Around the wall just within the margin is a row of refringent 

 points formed by slight thickenings of the perisarc within the 



