1909] Torrey: The Leptomedusat of tin San [>i<<i<> Region. 



13 



Gen. Ptychogena Agassiz, 1865. 

 Thaumantiidae with four radial canals which hear gonads in 

 the form of transverse folds. Mouth central; no gastric ped- 

 uncle. Tentacles without ocelli. Cirri absent. 



Ptychogena californica, n. sp. 



Figs. 1, 2. 

 Umbrella moderate, more than half as high as broad. Manu- 

 brium short, with thin walls; mouth large, without lobes. About 

 48 Large tentacles with thickened, compressed bases and slender 

 filaments. Between every two tentacles, 1-5 cordyli on promi- 

 nences of varying' size, resembling the bases of small tentacles. 



Fig. 1. — Ptychogena californica. Camera drawing of a 

 preserved specimen. X 4. 



Gonads with 12-14 folds in the proximal half of each canal. 



Diameter 10 mm. 



Distribution.— Oft San Diego. May 31, 1904. in a vertical 

 haul from 210 fathoms. Aee. No. 45. 



Two specimens only have been collected; they are of the same 

 size, with immature gonads. The cordyli resemble club-shaped 

 filaments of tentacles in an arrested state of development (fig. 

 2). Each cordylus arises from a base of varying height some- 

 what within the row of tentacles, yet between the latter. Neither 

 tentacles nor tentacle filaments are in good histological condition. 

 The former, however, appeal' to be typical, with large, non- 



