[60] 



MR. JAMES RITCHIE OX nYDROIDS 



[May 28, 



aud stout proximally, gi'adually narrow towards the opening, 

 which is fui'nished with two long, tliick-rimmed, lateral teeth. 

 The operculum is composed of two flaps, in this agreeing with 

 ISutting's description and differing from that of Versluys (1899, 

 p. 43), where only a single flap is mentioned. 



Gonosome. — The gonangia, which are characteristic, have not 

 been previously described. They are 1 mm. high, borne on short 

 stalks on the front of the stem, generally one on each internode. 

 and arise from near the base of a liydrotheca. They are strongly 

 compressed from back to front, .somewhat flask-shaped, with their 

 greatest diameter (0'6 mm.) near the base and gradually narrowing 

 towards the top, where a slight neck is surmounted by a flattened 

 di.sc bearing two long, incurved, honi-like spines. These are 

 placed, one on each side, immediately above the longitudinal 

 lateral ridge formed by the compression of the gonangium. The 

 gonangia are strongly ridged throughout, the ridges varying in 

 number from five to eight. The gonangial contents escape througli 

 a longitudinal slit with toothed edges, stretching along the flattened 

 top of the gonangium from " horn " to " horn." 



Text-fisr. 144. 



hlat. 



Male Gonosome ai SeHidarla vershti/si, 



ap., aperture with toothed lips through which gonanpial coutents escape ; «'., wall 

 of gonangium ; gub., gubernaculum ; sp., spermary ; col., central column of 

 gonophore ; JOB., gonophore ; ec*., ectoderm ; «nrf., endoderm ; 6;s<.,blastostyle. 



A peculiar modification was noted in one of the specimens 

 examined, where the distal and posterior portion of a branch- 

 internode had become free and was prolonged into a straight 

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