448 



MR. G. S. BRADY'S MONOGRAPH OF 



few small round papillae. Colour white. "Antennae and limbs similar to those of 

 C latissimmn." 



Length -^g- in. , I ■ 

 Hab. Galway Bay, off the Isles of Arran, in 10 fathoms water {G. S. B.). 



Like Sars, I at first took this to be the young of the following species ; but a minute 

 examination shows decided specific differences, which will be best appreciated by exami- 

 nation of the figures. One specimen only occurred in my dredgings. 



2. Cytheropteron LATissmrM (Norman). (Plate XXXIV. figs. 26-30.) 



Cythere latissima, Norman^ Nat. Hist. Trans. Northumb. & Durh. vol. i. p. 19, pi. vi. figs. 5-8; Brady, 



Trans. Zool. Soc. vol. v. p. 381, pi. Ixii. figs. 4 a-e. 

 Cytheropteron convexum, G. O. Sars, loc. cit. p. 80. 



British type. Distribution : Eece/i^— Baffin's Bay, Norway, Great Britain, Ireland. Fossil — Glacial, 

 Scotland, Norway. 



Lateral protuberance moderately prominent, obtusely angular behind. Carapace of 

 female, seen from the side, obliquely subovate, greatest height in the middle, and 

 equal to considerably more than half the length ; anterior extremity narrowed, rounded ; 

 posterior produced in the middle into an obtusely rounded angle. Superior margin 

 arched ; inferior convex, slightly sinuated in front of the middle. Outline, as seen from 

 above, subovate, angular behind the middle, thence suddenly tapering to the posterior 

 extremity, which is sharply pointed ; greatest width equal to more than half the length. 

 Yentral surface flat, often longitudinally striated. End view triangular, equilateral, base 

 flat, sides convex. Shell of the male more elongated. Colour white. Surface of the 

 valves marked more or less distinctly with oblong, slightly curved pittings, running in 

 transverse rows across the shell. "Second joint of the upper antennae about equal in 

 length to the fourth, the last very short. Second joint of the last pair of feet much 

 longer than the two following. Distal portion of the male copulative organs obtusely 

 truncated at the apex, the trifurcate spine narrow and shorter than the rest." 



Length in. 



Hah. In depths of from 10-80 fathoms. Shetland {Mr. J. G. Jeffreys) ; Aberdeenshire {Mr. Dawson) ; 

 Loch Fyne {Rev. A. M. Norman) ; Oban, Bute, Cumbrae, Macduff, Peterhead, and Ormeshead 

 (Mr. D. Robertson) ; Northumberland, Durham, and Yorkshire coasts (G. S. B) ; Norfolk coast 

 {Mr. D. 0. Drewett) ; in shell-sand from the River Ribble and Isle of Wight {Mr. E. C. Davison). 



A very pretty and well-marked species, distinguishable from the following (C. nodosttm) 

 by the less angular outline and the absence of any well-defined transverse ribs and nodes, 

 as well as by its larger size, — from C. punctatum also by its much greater size, less 

 pronounced lateral alae, and the character of the surface-marking. It has been wrongly 

 identified by G. O. Sars with Cy there convexa, Baird, a totally different species, which 

 has not yet been noticed on the Norwegian coast. 



3. Cytheropteron nodosum, n. sp. (Plate XXXIV. figs. 31-34.) 



Atlantic type? Distribution: Recent — Britain, Ireland. Fossil — Glacial, Scotland, Ireland. 



Similar to the preceding, but much smaller. Carapace of the female, as seen from the 



