292 PROCEEDINGS OF SOCIETIES. 



PLATE X. 



ILLUSTRATIVE OF A PAPER, BY J. R. KINAHAN, M.B., ON DUBLIN 

 CRUSTACEA. 

 Fig. 



1. Hippolyte variant, normal type ; rostrum nearly straight; apex bi- 



dentate, directed upwards, upper tooth shortest; below, two 

 teeth, the anterior much posterior to the upper tooth of apex ; 

 proportional frequency of occurrence, 63 per cent. 



1a. Peduncle of external antennae of ditto. 



1b. Median plate of tail of ditto. 



2. Eostrum straight ; apex tridentate, teeth directed forwards, upper 



and lower teeth nearly equal in length ; below, one tooth only ; 

 proportional frequency, 25 per cent. 



3. Rostrum strongly curved upwards, scimitar-shaped; apex triden- 



tate; upper tooth slightly longer than lower; below, a single 

 tooth; proportion, 8 per cent. "N. B. The whole animal is much 

 slenderer than the normal type : query, a species, 



4. Rostrum straight ; apex broadly truncated, directed forwards, qua- 



dridentate ; in plate wrongly represented as tridentate ; apical 

 teeth very minute ; below, two teeth ; proportion, 2 per cent. 



6. Rostrum straight ; apex acuminate, simple ; in plate wrongly repre- 



sented as bidentate ; directed upwards ; rostrum with two teeth 

 below. One specimen out of 300 examined. 



5. Rostrum straight ; apex bind ; rostrum with three teeth below, viz., 



one beneath apex, and two closely approximated in the broadest 

 portion of the rostrum. One specimen. 



7, 8. Rostrum of H. Cranchii. In Fig. 8, the two lateral spines 



omitted. 

 9, 10. Ditto, H.pusiola {Kroyer). Tooth over eye omitted in Plate. 

 11, 12, 13, 14. Rostrum of varieties of Palcemon squillce. 



Vide page 160. 



