182 Mr. E. W. L. Bolton the 



XXIL — Additions to the Invertebrate Fauna of St. Andrews 

 Bay. By EitNEST W. L. Holt, Assistant Natuialist to 

 the Royal Dublin Society's Fishery Survey, and late of 

 the St. Andrews Marine Laboratory. 



[Plate XI.] 



Professor M'Intosh, to whom I am indebted for the use of 

 the lilarine Laboratory during a stay of eighteen months at 

 St. Andrews, has asked me to furnish a brief record of such 

 forms, new to the local fauna, as came under my observation 

 during that period. They were obtained for the most part 

 by the use of the tow-nets or from the lines of the St. 

 Andrews fishermen, whose kindness in allowing us to over- 

 haul their gear and in bringing to the laboratory specimens 

 which had excited their own curiosity cannot be too highly 

 appreciated. 



Infusoria. 



On April 1, 1890, a specimen of Caligus rapax brought up 

 in the bottom tow-net was noticed to be beset posteriorly by 

 a number of foreign organisms which on close examination 

 proved to be Acinetid Infusorians apparently belonging to 

 the genus Hemiophrya. Figure 1 (PI. XL) rej)resents the 

 host and its cpizoic parasites as they appeared on the following- 

 day. On the day of capture most of the Infusorians were 

 covered in the apical region with gemmules, whicli had all 

 been liberated when the drawing was made. 



llemioyhrya is characterized by the possession of tentacles 

 of two orders, of Avhich the suctorial ones appear to be usually 

 very minute. In the specimens before us no suctorial tentacles 

 were discernible, and, judging from Saville Kent's figures 

 (' Manual of Infusoria,' pi. xvii.), this is occasionally the case 

 with other species of this genus. 



Sir John Dalyell, in ' The Powers of the Creator displayed 

 in the Creation' (vol. i. p. 249, pi. Ixvi. fig. 10), mentions 

 and figures " a minute zoophyte " from the dorsal region of a 

 Caligus. I think that a glance at his figure leaves no doubt 

 but that he was misled, as I was at first myself, by the 

 resemblance of the form before us to a Ilydroid. As our 

 form does not agree exactly with any other species of which 

 I have been able to find a description, I would propose to 

 name it after its first observer. 



Hemiophrya Dalyelli, sp. n. (PI. XL figs. 1-4.) 

 Pedicle or tube hyaline, finely granular, not striated, 



