1878.] MR. E. J. MIERS ON THE PEN^EIDjE. 307 



§§ The carina between the base of rostrum and posterior margin of the cephalo- 

 thorax not sulcatc, and often not reaching to the posterior margin. 



* Rostrmn with the inferior margin dentate. (No lateral sjrines on last fjost- 



abdominal segment.) 



Rostrum ^p^-dentate. Terminal segment ending in a long spine. 



*7. P. setiferus, Linn. 

 West Indies, east coast of North America. 



Rostrum ^ dentate, not reaching beyond the antennal scale. Terminal 



segment acute. 



8. P. monodon, Fabr. 

 Indian and Australian Seas. 



Rostrum very slender and styliform in its distal half, — L -dentate and reach- 

 ing slightly beyond the antennal scale. 



9. P. indicus, M.-Edw. 

 Indo-Malayan Seas ; Panama ? 



** Rostrum with the inferior margin entire. 

 1. Rostrum not reaching far beyond the end of the antennal scale. 



Rostrum ensiform, straight, 8-10-dentate above, the teeth extending along 

 nearly the whole upper margin. Terminal postabdominal segment without 

 lateral marginal spines. 



10. P. monoceros, Fabr. 



Indo-Malayan Seas. 



Rostrum curved upward toward apex, 8-dentate above, dorsal carina reach- 

 ing nearly to the posterior margin. Terminal segment as in P. monoceros. 



*11. P. curvirostris, Stimpson. 



Japan, Simoda. 



Rostrum robust, curved slightly upward, 8-9-dentate above, the last tooth 

 situated on the dorsal carina at considerable distance from the preceding. 

 Terminal segment with a pair of lateral spines. 



12. P. membranaceus, Risso. 

 Mediterranean, Madeira. 



Rostrum styliform at apex, nearly straight, 7-9-dentate above in its proximal 

 half. Terminal segment without lateral marginal spines ; 5th legs (in the 

 female) rudimentary. 



13. P. dobsoni, Miers. 

 West Coast of India. 



Rostrum slender, styliform and produced at apex, 6-9-dentate above at its 

 base. Terminal segment with prominent lateral marginal spines ; 5th legu 

 (in the male) long and slender, dactylus small. 



1 4. P. stylifcrus, Edw. 

 Bombay. 



2. Rostrum reaching far beyond the end of the antennal scale. 



Rostrum 9-10-dentate above ; the 3-4 last teeth placed upon the slender 

 styliform distal half. Last postabdominal segment with lateral spines. 



*15. P. foliaceus, Risso. 

 Mediterranean. 



Rostrum 6-dentate above, the styliform distal portion without teeth. Ter- 

 minal segment without lateral spines. 



16. P. kroyeri, Heller. 

 Brazil West Indies. 



b. Cephalothorax without any median dorsal ridge. (Rostrum entire below.) 

 Rostrum straight, dentate nearly to its apex; first tooth separated by a 



20* 



