464 Mr. E. T. Browne on the MedoKm 



stage\ As there is no evidence to show that Agassiz reared 

 tlie medusae in an aquarium, I presume that this later stage 

 was taken out of the sea. It has sixteen tentacles and a 

 cirrus between every two tentacles. The basal bulbs of all 

 the tentacles are provided with ocelli ; but there are no 

 cordjli. It seems to me that the similarity between the 

 above two stages is the presence of ocelli, and it is well to 

 remember that there are other genera besides Laodice with 

 dark ocelli on the basal bulbs. 



^ Mefschnikoff (1886, p. 83, Taf. iv. figs. 17-31, Taf. v. 

 iig. 1) has given an excellent description of the development 

 of the ova of Laodice crueiata and splendid figures of tiie 

 hydroids which he reared from the ova. His work is entirely 

 embryological, and no description of the medusa is given. I 

 presume he means Laodice crueiata according to Ha^ckel, and 

 that his species was really Laodice mediterranea of Gegen- 

 baur ; for this is the only species of Laodice among Hgeckel's 

 many synonyms. The hydroid which Metschnikoff reared is 

 similar to CusjAdella humilis, Hincks. 



Hincks (1868) described three species of CuspideVa — 

 C. humilis, C. costafa, and C. grandis. The descriptions are 

 based upon the shape of the hydrothecfe. It is evident to me 

 that the sliape of the hydrotheca of Cuspidella and its allies 

 is not sufficient to base specific characters upon, and that the 

 structure of the hydranth must be taken into consideration, 

 and also tiie gonosome. It is quite likely that Cuspidella 

 costata is only another form of C. humilis. For the purpose 

 in view it is sufficient to know that Metschnikoff reared 

 from the ovum of Laodice a hydroid belonging to the genus 

 Cuspidella, which is distinguished generically from Agassiz's 

 Lafoea by the presence of an operculum on the top of the 

 hydrotheca. 



During June 1906 I received a letter from Miss M. Delap, 

 of Valencia Island, stating that she had kept a colony of 

 Cuspidella costata under observation and had seen the colony 

 liberate medusae. Later on I received drawings of the 

 hydroid and its medusa and also specimens. The hydro- 

 theca is like Hincks's figure and has a few transverse rings 

 and an operculum. The gonotheca is somewhat similar to 

 the hydrotheca, but is about twice the length and is without 

 transverse rings. The figure drawn by Miss Delap shows 

 two medusa-buds inside the gonotheca and a medusa just 

 escaping through the operculum. The medusa on liberation 

 has two opposite perradial tentacles and two opposite per- 

 radial tentacular bulbs. On each side of the two tentacles 

 there is a cirrus, adradial in position, and cirrus-buds occupy 



