I id ci;\ LON PEARL OYSTEB REPORT. 



(I>.) [Jmbrella about .'! millims, in diameter. Peduncle about 6 millims, in length. 

 Gonads jusi appearing upon the pedunole and sub-umbrella. About L2 marginal 

 bulbs in eaoh quadrant . 



'Tins speoies docs not agree with EIaeokel's definition of the genus Octorch%s, since 

 ii has only I instead of 8 tentacles, bu1 in other respeots it conforms to the generio 

 oharaoter. Octorchxs gegenonwi lias been frequently taken l>v me m British seas. 

 Early and intermediate stages (the latter often with gonads) have I tentacles, 

 whereas the fully developed adult has 8 tentacles. I think it would be better to 

 enlarge the generic oharaoter so as to include speoies with I and 8 tentaoles, than to 

 establish a Dew genus for speoies which have only I tentaoles. 



Haeokel, in his monograph, mentions two speoies of Octoi'chis 0. gegenooywn and 

 0, ccvmpnwulcitus, both ooourring in the Mediterranean, but probably there is only one 

 species. The Bpeoimens from Ceylon arc distinguished from the Mediterranean 

 species by the greater length of the gonads on the pedunole. 



Irene, Ksciisciioi.t/., I S - J!'. 



Irene eeylonensis, n. sp, Plate III., figa 9 to I I. 



Description. Umbi'ella probably watohglass-shaped, much broader than high, 

 with thin walls. Velum narrow. Stomaoh short, situated upon a long cylindrical 

 pedunole. Mouth with Pour lips, winch have a folded margin, Four radial canals. 

 Gonads linear, extending from the base of the peduncle to near the margin of the 

 umbrella. Tentaoles about too. Cirri absent. Sensory vesioles, one between every 



two tentacles, each vesicle with a Single otolith. 



Size; Umbrella up to aboul 25 millims, in diameter. 



Locality: (Jalle Bay, one specimen on .1 ulv I . ; I'heval l'aar, five ID November, 

 Notes, The collection contains six specimens differing in age and size, the smallest 



being aboul .> millims. m diameter, All the specimens are more or less damaged. 



They are in a fair state of preservation, but are stained dead black, probably Owing 



to the use of osmio acid, 



The umbrella is llat and thin, hut is no doubt slightly curved when the medusa is 

 alive. Only one specimen show s I he peduncle fairly well, the others have either lost 

 it 01 have it twisted up. The gonads form thin narrow hands, either Btraight or 

 sinuous, extending along the radial canals over the sub-umbrella. In the largest 

 specimens the ova are large and clearly visible. Some o( the specimens have a 



marginal l>ulh between some <>t' the tentacles, and these bulbs I believe to be the 



origin of new additional tentacles, and not warts or tubercles, which Ao not develop 

 tentacles. 1 am doubtful about the presence of excretory pores at the back of the 

 basal bulbs, as there were no indications >>f papilla', but they may be contracted. 



