524 ]\rr. J. Ritcliie on n^w Hydroida Thecita 



LXIX. — New Species and Varieties of Hi/droida TJiecnta 

 from the Andaman Islands. By James Ritchie, M.A., 

 B.Sc, Natural History Department, the Royal Scottish 

 Museum. 



In a collection of Hydrolds kindly entrusted to me for 

 identification by Dr. Nelson Annandale, Superintendent of 

 the Indian Museum, there were contained such specimens as 

 had been dredged in the deeper waters of the Indian Ocean. 

 Of the twenty-four distinct forms in this collection I regard 

 four as new species and two as undescribed varieties. Fuller 

 descriptions of these, with figures, will be publisiied, along 

 witii the report on the rest of the collection, in an early 

 number of the ' Records of the Indian Museum,' the object of 

 the present notice being merely to chronicle the occurrence 

 of a few interesting undescribed additions to the little-known 

 deep-water Hydroid fauna of Indian seas. 



CampanularidaB. 

 Hehella crateroides, sp. n. 



Trophosome. — Colony epizoic, with a creeping hydrorhiznl 

 tube, which meanders over the stems and branches of other 

 Hydroids. The hydrothecse, which arise at irregular intervals 

 from the stolon, are small and colourless, like a wine-glass in 

 shape, with firm walls marked in some cases by exceedingly 

 faint corrugations, and gracefully everted round the margin. 

 As the hydrotheca gradually diminishes in diameter from the 

 margin almost until the hydrorhizal tube is reached, the 

 hydranthophore is not distinctly indicated ; and tiie hydro- 

 theca cavity is separated from the common cavity of the 

 colony only by a delicate film. The hydranth bears from 

 about 6 to 8 tentacles. 



Oonosome. — The gonangia, which are borne on short 

 indetinite stalks, are at least three times as large as the 

 hydrothecse. They are roughly cylindrical in shape and 

 have irregularly corrugated walls, with an everted margin. 

 Three medusee, as a rule, develop from each blastostyle. 

 The manubrium is large and four stout tentacles are present 

 ere the medusa is set free. 



This species is closely related to Hebella calcarata (A. 

 Agassiz), from which it may be distinguished by the much 

 Bmaller number of tentacles possessed by its hydranth and by 

 the inverted-cone shape of its hydrotheca. 



