406 



MR. G. S. BRADY'S MONOGRAPH OF 



subtriangular ; anterior extremity lengthened into a slender and obtusely pointeu 

 process." 



Length ^ in., height in. i%~ vv-^^- 



Hab. In deep water. Isle of Skye and Northumberland and Durham coasts {Rev. A. M. Norman) ; Oban 

 [Mr. D. Robertson) ; Aberdeenshire coast {Mr. Dawson) . 



This species appears to live altogether amongst soft mud, in which it burrows, whence 

 probably, as Sars observes, the entire absence of eyes. Like the preceding species it is 

 of rare occurrence in the British seas ; and Sars makes the same remark respecting its 

 Norwegian distribution. It occurs also in the Scotch glacial clays. I now believe that 

 the form described by me as C. complexa is merely the young of C. limicola (see 

 figs. 43-46). 



14. Cytheue globtjlifera, n. sp. (Plate XXXI. fig. 42.) 



Valves, as seen from the side, oblong, subrhomboidal, rather higher in front than 

 behind ; greatest height equal to more than half the length. Extremities rounded, the 

 posterior rather narrowed; superior margin straight, gibbous over the anterior hinge; 

 inferior slightly convex, curved upwards behind. Surface marked with a fine ribbed 

 reticulation and bearing four prominent rounded tubercles, three below the dorsal and 

 one above the anterior extremity of the ventral margin ; the shell is swollen below and 

 behind the middle into a rounded elevated ridge or ala. 



Length 5^3- in. , 

 Hab. Roundstone, in shell-sand. 



Of this species I have seen only one specimen, and that a single valve; but its 

 characters are so very different from those of any described form, that I have thought it 

 best to describe it here under a specific name; it is nevertheless possible that it may 

 prove to be an immature form of some other species*. 



** Mandibular palp four-jointed, last joint slender ; inner margin bearing three strong, curved, plumose 



setce. Urticating setm much shortened in the female. 



15. Cttherb tuberculata (Sars). (Plate XXX. figs. 25-41.) 

 Cythereis tuberculata, G. O. Sars, loc. cit. p. 37. 



Cythere mutabilis, Brady, Trans. Zool. Soc. vol. v. p. 377, pi. lix. figs. 12-14. 



British type. Distribution : Recent — Baffin^s Bay, Great Britain, Ireland, Norway, Bay of Biscay, 

 West Indies. Fossil — Glacial clays and raised beaches, England, Scotland, Ireland, and Norway. 



Shell of the female, as seen from the side, elongate quadrangular, highest in front ; 

 greatest height equal to more than half the length ; a large rounded tubercle in front of 

 the centre, and two elongated tubercles or ridges, one ventral and one dorsal, near the 

 hinder extremity ; these last are very conspicuous in young specimens, but become 



* Since writing this, I have had the opportunity of examining several specimens, apparently referable to this species, 

 which have been found by Messrs. Crosskey and Robertson in the course of their researches amongst the Scottish 

 glacial clays. 



