Fam. 3, Plate 14. 



EOLIS RUFIBRANCHIALIS, Johnston. 



E. gracilis, elongata, alba : branchhs linearibus, coccineis, apicibus albis, in fasciculis 6-7 indis- 

 tinctis digestis : tentaculis dorsalibus corrugatis : angulis anterioribus pedis curtis. 



Eolidia rufibranchialis, Johns., in Loud. Mag. Nat. Hist. v. 5, p. 428. 

 Idem, in Ann. Nat. Hist. v. 1, p. 121. 



Eolidia Emhletoni, Idem, in Loud. Mag. Nat. Hist. v. 8, p. 379. 



Hab. Under stones in pools at low-water mark, and in shallow water. Berwick Bay, Dr. Johnston. 

 Whitley and Cullercoats, rather rare. Lamlash Bay, Rev. D. Landsborough. 



Body about an inch long, very slender, and tapering to an exceedingly fine point ; trans- 

 parent watery white, appearing yellowish in the centre, from the viscera shining through ; an 

 opake white line passes along the ridge of the back from the heart to the end of the tail. 

 Dorsal tentacles moderately long, tapering, wrinkled transversely, and set at a little distance 

 apart ; of a yellowish white, sometimes tinged with rose colour, and having an opake line of 

 white on the upper part of the posterior surface. Oral tentacles of about an equal length 

 with the dorsal pair, transparent white, with an opake white central line ; rather depressed 

 and separated by the rounded outline of the head. Branchice rather short, slender, nearly 

 linear ; the central vessel scarlet or rose red, with the margins much undulating ; the sheath 

 transparent, and having a slender opake white ring near the apex. They are set in six or 

 seven ill-defined clusters on the sides of the back ; and are arranged in transverse rows, the 

 largest containing about four papillae each : in the first cluster there are six or seven rows ; 

 in the next, four ; and two or three each in the others. Foot very transparent, linear, and 

 extending considerably beyond the branchiae into a very slender point behind ; in front the 

 margin is slightly bilobed, slit transversely, and a little produced at the sides, ending in small 

 points. 



This is one of the most slender and delicate forms of the genus. It is met with 

 on the rocks near low-water mark in April, May, and June, when it has attained its 

 full growth, and is spawning. The spawn is attached to the under surface of stones in 

 pools, and resembles that of E. coronata, but is more openly coiled, and the band or thread 

 of eggs is less undulated. In August and September, the young are found considerably 

 advanced. 



This beautiful species has been much misunderstood. We agree with Dr. Johnston in 

 uniting his E, Emhletoni and E. rufibranchialis, yet we suspect that he has included more 



