HAl.OCOlfDYLE COOPEIU. 11 



Tlio chief food of the hydroid appears to be copepods. As 

 far as coukl be ascertained from my sections, dig-estion takes 

 place solely in the dig-estive cavity, the ])ieces of food never 

 being found in the epitlielium. In some sections recently cut 

 of an Eudendrium, which feeds on similar organisms, the 

 separate eggs of the egg-clusters of the devoured copepods 

 are seen to have been taken bodily into the eudodermal 

 epithelium. 



(3) Gronosome. — The female gonophore is long and ovate. 

 In P. cavolinii it is phanerocodonic, but in the present 

 species I have never found the umbrella cavity open to the 

 exterior, and it is therefore probably adelocodonic. The 

 hydroid is far from common, and consequently I have not 

 had an unlimited supply of material. Unfortunately, I have 

 not seen a gonophore empty of its contents, but I think there 

 can be little doubt that it is adelocodonic. The section of an 

 a])|)arently ripe gonophore (fig. 4) gives no impression of any 

 further development. The gonophores arise from the base of 

 the polyp just above the verticil of filiform tentacles. There 

 are four radial canals, but no circular canal. The radial 

 canals are not connected together by an endodermal lamella 

 (fig. 5). The umbrella cavity is lined externally by a definite 

 ectodermal epithelium {e. e) . Apically the radial canals slightly 

 expand, and contain a deeply staining gelatinous (?) mass 

 (fig. 4, g. m), which is probably of the nature of a basal bulb. 

 No rudiment of ocellus has been detected. The spadix is well 

 developed, and is covered with germinal epithelium four or 

 five layers thick. 



The germinal epithelium arises in situ as a thickening of 

 the ectoderm of the young gonophore bud (fig. 4, e. u). I 

 have been unable to observe an}- migration or wandering of 

 sexual cells. 



Since the above paragraph was written I have obtained 

 specimens of the male colony, which appears to be much 

 scarcer than the female. Out of some thirty colonies col- 

 lected eight Avere females, two wei-e male, and the remainder 

 were undetermined as they were not producing gonophores. 



