30 Bulletin, Vanderbilt Marine Museum, Vol. IV 



Comp. Zool., vol. 8, p. 156, pi. 5, figs. 5, 6, 11, 12, 1881; Mem. 

 Mus. Comp. Zool., vol. 9, pi. 5, figs. 7, 19, 1884.— Hargitt, Bull. 

 U. S. Bur. Fish., vol. 24, p. 25, 1904.— Mayer, A. G., Medusae of 

 The World, vol. II, p. 335, pi. 44, figs. 1-4, color plate, 1910 ; Publ. 

 109, Carnegie Inst, of "Washington. 



HYDROIDA. 



Family: PLUMULARIIDAE. 



Genus : CLADOCARPUS Allman. 

 Cladocarpus sigma (Allman). 



Plate 2. 



Type: Allman 's type came from Florida and is deposited in the 

 Museum of Comparative Zoology. 



Distribution : Florida and the upper West Indian region. Bathy- 

 metric occurrence: 110 to 352 fms. 



Material examined : Two small colonies taken in 150 fms., 7 miles 

 S. W. off Alligator Reef, Florida, March 31, 1926. 



Color: Crystalline, transparent. 



Technical description : According to Nutting this species attains 

 a height of two to two and one-half feet, branching profusely and 

 repeatedly. The "Ara" specimens are broken branches 80 mm. and 

 87 mm. high, respectively. 



Trophosome : Colony pinnate, stem fascicled except at the extreme 

 tips of the branches; hydrocladia alternate, closely set, originating 

 from the front side of stem ; internodes straight, each having its axial 

 cavity divided by about ten very strong and conspicuous septal ridges, 

 which appear to extend entirely around the internal surface of the 

 internode. Hydrothecae rather closely approximated for this group, 

 deep, cylindrical, with the margins cut into about ten shallow teeth, 

 sharp pointed with shallow arcs between; margin slightly flaring; 

 intrathecal ridge conspicuous with a sigmoid flexure in lateral view 

 its course being curved forward then upward then forward, down- 

 ward and forward again; the supracalycine nematophores are cylin- 

 drical, reaching the margin of the hydrotheca; the mesial nemato- 

 phores are small, spur-like, adnate except at the distal end ; the cauline 

 nematophores afford no specific characters. 



Gonosome: Gonangia are present on one of the specimens; they 

 are borne on phylactogonia, springing from the proximal internode of 



