neio Fishes frovi the South-west Coast of Ireland. 91 



i. L. 1. ca. 102. Tnterorbital area over- 

 lying ethmoid region and bounded by 

 prefrontals and t'rontals, almost rectan- 

 gular. No tubercles on belly at [(Gilch.). 

 108 mm. (without caudal) 3. C. rhomboidalis 



ii. L. 1. ca. 80- 8o. Interorbital area over- 

 lying ethmoid region and bounded by 

 prefrontals and frontals, lanceolate. 

 No tubercles on belly at 200 mm. 

 (without caudal) 4. C. helgcp, sp. n. {infra), 



Cyttosoma helgcf, .sp. n. (PI. III.) 



Head moderately, body greatly elevated and compre.ssed ; 

 greatest width in opercular region ; anterior profile from 

 above eyes to origin of dorsal fin concave ; bases of dorsal 

 and anal fins nearly straight. Length of head without jaws * 

 about 3 in total length (witiioiit jaws * and caudal fin), about 

 twice in distance from origin of second dorsal spine to origin 

 of ventral spine, and about 2i in distance from origin of 

 second dorsal spine to origin of first anal spine. Snout 

 (without jaws) about twice in horizontal diameter of orbit f 

 and nearly 4i times in head (without jaws). Vertical 

 diameter of orbit about f of horizontal diameter and about 

 equal to width of interorbital space. Caudal peduncle about 

 as long as orbit; its length about double its depth and three 

 times its width. 



Median area of interorbital space lying between the rather 

 broad frontals and prefrontals and bounded posteriorly by 

 the frontals, lanceolate, slightly convex, and covered with 

 small very rough scales. All the exposed bones of the head 

 and gill-cover granular or rugose, with their exposed margins 

 finely but bluntly and irregularly denticulated. No distinctly 

 projecting ridge on operculum. MuxiUa extending to below 

 front of eye, with a central rugose area not extending to its 

 edges. ]\routh protrusible, when completely closed projecting 

 but little (about ,\ horizontal diameter of eye) beyond pre- 

 orbitals. Botli jaws with a few small and obsolescent teeth ; 

 vomer toothless. Suborbital wide, its vertical measurement 

 below centre of eye about \ vertical diameter of orbit. 



Dorsal fin originating slightly behind vertical from vontrals, 

 VII 34 ; the second spine very stout, longitudinally striated, 

 and as long as horizontal diameter of eye ; articulated raya 



* It seems best to adopt this standard of length, as the jaws are often 

 protruded in preserved specimens and cannot bo closed without risk of 

 injury. The front edge of the preorbital is always well defined. 



t The marked bulging of tne eyes in some species of this genus is 

 plainly, in part at least, caused by" circumstances attending capture in 

 (le(<p water. 



