HYDROZOA — RITCHIE. 827 



slender branches, up to 5 cm. in length, which in all respects, 

 ^except robustness, resemble the stem, bearing pinnate branchlets 

 to the third degree. Stem, pinnte, and branches are fascicled, 

 although a considerable portion of each termination remains free. 

 Many of these pinuate colonies grow in association, and as their 

 connection is secured by abundant anastomosis, a flabellate mass 

 15 cm. in breadth may be created. 



The minute characters agree with the description of Grypto- 

 laria conferta by Ailman, amended by later observers. The 

 hydrothec^ are long and slender, having, as a rule, about one- 

 third of their length free. They are regularly alternate and are 

 ■close-set, the base of one hydrotheca lying opposite the point 

 where the preceding hydrotheca becomes free from the stem. 

 "They are cylindrical for the greater part, but narrow slightly 

 towards the base, the diameter of the adnate portion equalling 

 that of the axial tube at the same level. The inner wall of the 

 hydrotheca ends abruptly with a slightly thickened knob, and 

 the " distinct floor " of the hydrotheca, which Ailman describes 

 and figures, is absent, as Clarke noted in specimens of Crypto- 

 laria conferta from the Gulf of Mexico, Versluys in Testigos 

 Islands specimens, and as Campenhausen found, exceptionally, in 

 •examples of the same species from Ternate. The hydrotheca 

 curves gradually and gracefully outwards from base to termina- 

 tion, and its round, smooth aperture varies from a position 

 parallel to the long axis of the branch to an upwards inclination 

 ■of 30°. The latter position is the more usual, however, for the 

 former is brought about only by the unequal growth of repeated 

 fresh. margins, of which sometimes as many as eleven are present. 

 In these specimens perforations connect the cavities of the peri- 

 pheral with those of the axial tubes, though I am unable to 

 ■confirm the existence of the regular arrangement which Clarke 

 ■claimed for them. 



As the hydranth of Cryptolaria remains undescribed, except 

 for an observation on that of Cryptolaria operculata which I 

 have recently recorded,!^ I do not hesitate to add a note on the 

 rather poorly preserved hydranths of Cryptolaria conferta before 

 me, notwithstanding that those of the following species are more 

 fully described. In the state of contraction in which all are, 

 they appear as elongate cylindrical bodies with seven to nine 

 short tentacles surrounding a low, dome-shaped hypostome. The 

 ectoderm is thin throughout, but elongated endoderm cells project 

 into the digestive cavity Vjeneath the level of the bases of the 

 tentacles. The hydranth narrows somewhat proximally, and is 

 terminated by a wider ccenosarcal disc which is attached to the 



» 3 Ritchie— Rec. Indian Mus., v., 1910, p. 10. 



