MARSHALL : ADDITIONS TO " BRITISH CONCHOLOGY." 135 



centre ; rarely the shell is of a uniform reddish brown. Jeffreys' 

 figure shows one band on the penultimate whorl, but he does not 

 mention it in his description. Sowerby's has two bands on the pen- 

 ultimate whorl and one on the next, which is right ; but the bands on 

 these upper whorls can only be seen on clean and transparent speci- 

 mens ; they are never so vivid as on the last whorl, and the dried 

 remains of the animal prevents their appearing well defined. Jeffreys 1 

 has recorded a var. efasciata, found by Mr. Webster in South Devon. 

 This is of a uniform reddish brown, and occurs very sparingly. 



R. obtusa Cantr. — It is now generally conceded that our species 

 is not the one which was described by Philippi as R. soluta, though 

 Jeffreys prefers to retain the latter name for it on the ground that 

 Cantraine described the aperture of his R. obtusa as " obliqua," and 

 the peristome as " continuo," neither of which characters are appli- 

 cable to our shell ; but it is not easy to assign those characters to any 

 other species in this section. Strangely enough, too, neither of the 

 above authors " noticed the spiral strife nor the umbilical chink," 

 although "Philippi illustrated his description by a figure." The true 

 R. soluta Phil, is well figured by S. Wood in " Crag Mollusca" as 

 R. obtusa, with doubts as to whether it is the same as the recent 

 British species ; while Forbes and Hanley, who figure R. obtusa excel- 

 lently, also express themselves in doubt as to its being the Mediter- 

 ranean species. R. soluta Phil, is very closely allied to R. intorta 

 Mtros., if it is not the same thing. 



Scilly and Channel Islands ; Falmouth ; Eddystone ; Torbay ; 

 Isle of Man and Lancashire coast; Doggerbank; Bantry Bay; Conne- 

 mara ; Mayo ; Sligo ; Portrush ; Dornoch Frith ; West Orkneys. 



A gregarious species, and variable in size, some specimens being 

 four times the bulk of others. The smallest come from the Eddy- 

 stone, and the largest from Guernsey and the Minch. Some speci- 

 mens are oblong, while others at the extreme scale are nearly 

 globular, having the same outlines as R. triangularis Wats. 



R. semistriata Mont. — Scilly Islands (Smart and others) ; Dor- 

 noch Frith. 



Var. pura Jeffr. — Not uncommon in the Channel and Scilly 

 Islands. 



There are three forms of this species, mostly found together. The 

 first is 0-15 inch long by half that width; this I consider the type, 

 and it is the one figured by Sowerby. The next is smaller and more 

 slender, and may be the male ; it agrees with the figure and dimen- 

 sions given by Jeffreys. The third is a dwarf, about half the size of 

 the preceding. 



1 Ann. Mag. N. H., (3), vol. 4, p. 196, 1859. 



