62 AMERICAN HYOEOIDS. 



throughout, the annulations being often more sparse in the median portion, and decrease 

 regularly in size from the proximal to the distal ends. The hydrothecse are deeply campanulate, 

 the distal parts being almost tubular, and are more than twice as long as wide. The margin 

 bears about 14 well marked, pointed teeth and there is a well-defined diaphragm and rather 

 low basal chamber. The hydranth has a tnimpet-shaped proboscis and about 24 tentacles. 



Gonosome. — The gonangia are borne on the stem and branches. They are oblong ovoid 

 in shape with the distal end abruptly truncated. The walls are often somewhat corrugated 

 transversely, but not regularly annulated. They are about 1.25 times as long as the hydro- 

 thecse and somewhat broader. Gonangial contents, developing medusse, the details of which 

 can not be made out. Torrey says that the oldest have 4 tentacles. 



Type-locality. — San Pedro Bay, California. This species has not been reported from 

 any other locality except San Diego Bay, California. 



CLYTIA FRAGILIS Congdon. 



Plate 15, fig. 1. 

 Clytiafragilis Congdon, The Hydroids of Bermuda, 1907, p. 470. 



Trophosome.^ — Colony 9 mm. in height (Congdon's specimens were 12.18 mm). The 

 basal portion is lacking, and the specimen divides into two subequal branches near its proxi- 

 mal end. These branches are divided into sinuous iaternodes each of which bears a pedicel 

 near its distal end and a group of annulations on its basal portion. The pedicels are alter- 

 nate in position, about as long as the hydrothecae or longer, diminishing in diameter from the 

 proximal to the distal end and extensively annulated, sometimes completely so. In most 

 cases, however, there is a median smooth portion. The hydrothecse are deeply campanulate, 

 almost tubular, often more than tmce as long as broad. The margin is armed with about 12 

 acutely pointed teeth which sometimes appear to be the terminations of compressed ridges 

 which lie vertically on the distal part of the hydrothecal walls. The diaphragm is evident and 

 rather high. 



Gonosome. — Gonangia borne on the stem near the axils of the pedicels. They are rather 

 slender, obconical in shape with the greatest diameter at the distal trimcated end. They 

 are about twice as long as the hydrothecse, and are borne on a very short annulated pedicel. 

 Gonangial contents developing medusse, according to Congdon. They were not in condition 

 to study in the specimen described. 



Distribution. — Type-locality, Bermuda Islands, growing on Pennaria tiarella. Albatross 

 station 2283, lat. 35° 21' 20" N.; long. 75° 23' 50" W., 14 fathoms. Fish Hawk station 6059, 

 Mayaguez Harbor, Porto Rico, 7 fathoms. 



CLYTIA HENDERSONI Torrey. 



Plate 15, figs. 2, 3. 



Clytia hendersoni Torrey, Hydroids of the San Diego Region, 1904, p. 18. 

 Clytia hendersoni Fraser, West Coast Hydroids, 1911, p. 35. 



TropTiosome.'^ — Colonies consisting of upright stems springing from a creeping rootstock. 

 Stems often irregularly branched, m which case the branches conform in detail to the stems 

 from which they spring. Height of stem 9 mm. Stem usually flexuose with a group of an- 

 nulations above each pedicel origin. Pedicels alternate, shorter than the hydrothecse, amiu- 

 lated throughout and formuig a very acute angle with the stem. Hydrothecse large, deeply 

 campaiiulate, approaching a tubular form, about twice as long as broad. The margin bears 

 12-14 very long, slender-pointed teeth the points of wliich are often turned inward and braced 

 by a sort of heel on the outer side. The diaphragm is high and strongly marked, bearing a 

 large basal chamber. Hydranth with about 24 tentacles. 



' Description of a specimen collected by the U. S. Fish Commission Porto Rico Expedition at station 6059. 

 ^ Description of a specimen kindly sent the author by Doctor Torrey from San Diego Bay, California, the type- 

 locality. 



