SYNDICTYON. 177 



observed on the Hyclrarium in March ; no young Medusae have been 

 observed; the adults attain an enormous size, meas- Fig . 289 _ 



uring more than an inch in polar diameter, as in Fig. 

 289, which is drawn the natural size. 



The spherosome bulges very rapidly from the abacti- 

 nal pole (Fig. 289) till it reaches the point of junction 

 of the chymiferous tubes ; from there it tapers very 

 gradually towards the peripheric tube ; the chymiferous 

 tubes are exceedingly slender, the digestive cavity very 

 long, projecting one half its length beyond the circular 

 tube, swelling near the lower extremity, and then sud- 

 denly contracting, tapers gradually, in the form of a 

 conical projection, beyond the ovaries ; the sensitive 

 bulbs are large, the eye-specks small. The proboscis 

 and the tentacles are of a dirty-yellow color, the color 

 of the swelling of the proboscis and of the sensitive 

 bulbs being somewhat darker. It resembles Sarsia 

 tubulosa of the English coast more than Sarsia mira- 

 btiis of New England. Found in the Straits of Rosario 

 in May, and as late as the beginning of July in the 

 Gulf of Georgia, W. T. ? and also in the harbor of San Francisco during 

 November. 



San Francisco, Cal. (A. Agassiz) ; Gulf of Georgia, W. T. (A. Agassiz). 



Cat. No. 48, Gulf of Georgia, W. T., May, 1859, A. Agassiz. Medusa. 



Cat. No. 49, San Francisco, Cal., March, 1860, A. Agassiz. Hydrome- 

 dusariuni. 



SYNDICTYON A. AGASS. 



Syndictyon A. AGASS. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p 340. 1862. 



Syndictyon reticulatum A. AGASS. 



Syndictyon reticulatum A. AGASS. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 340. 1862. 



The Hydrarium (Fig. 290) resembles that of Coryne mirabilis ; it is 

 much smaller, not being more than one tenth of an inch in height ; it 

 does not branch, or only occasionally once, near the base, in very old 

 specimens. The stem is slender, the head large, club-shaped, the tenta- 

 cles short, eight or ten in number. The Medusae develop among the 

 tentacles in the low r er part of the head ; this development is similar to 

 that of Sarsia ; when the Medusa is separated it is nearly as large as 

 the whole Hydrarium, measuring about one sixteenth of an inch in 



Fig. 289. Coryne rosaria, natural size. 

 NO. n. 23 



