65 



GENUS ACH2EUS: snout not much lengthened, and on 

 each side leaving uncovered the insertion of the stalk of the 

 external antennse. The terminal articulation of the two 

 posterior pairs of legs is large, compressed and falciform. 



CRANCH'S SEA SPIDER. A. Cranchii. M. Edwards' 

 Crust, vol. 1, p. 281. Leach's Malac. pi. 22. A rare spe- 

 cies, the only British recorded specimen having been taken 

 at Falmouth. 



GENUS INACHUS : differing from the two former genera 

 in having retractile eyes capable of extensive motion, second 

 pair of legs thrice as long as the post-frontal portion of the 

 carapace ; terminal portion of the four hinder pairs similar 

 and slender. 



SCORPION SEA SPIDER. I. Scorpio, M. Edwards' 

 Crust., vol. 1, p. 288. I. Dorsettensis, Leach's Malac. pi. 

 22. Cancer D, Pennant, pi. 9, fig. 18. Commonly taken 

 in crab pots within a few miles of the shore at all depths. 



FEEBLE INACHUS. /. Dorynchus, M. Edwards' Crust., 

 vol. 1, p. 288. Leach's Malac, pi. 22. Not uncommonly 

 found on board crab boats. Except in the rostrum it has 

 much of the aspect of Stenorrhynchus Longirostris, but is 

 less common. 



SMALL SNOUTED INACHUS. J. Leptorhynchus, M. 

 Edwards' Crust., vol. 1, p. 289. Leach's Malac, pi. 22. 



M. Edwards assigns this species to the west of England, 

 where it must be rare unless it has been confounded with the 

 other Sea Spiders. In the Athenaeum at Plymouth I was fa- 

 voured by Dr. Edward Moore with the sight of a specimen 

 marked by Mr. Prideaux with the name of I Leptochirus, 

 wbich is aUo figured by Dr. Leach as having been taken on 

 the Cornish coast, and of which I possess a specimen; but 

 whether, as seems probable, this be M. Edwards', I. Lepto- 

 rhynchus I hesitate to decide. The latter author, has not re- 

 ferred to Leach's name. 



MAIANS— SEA SPIDERS, continued. 



GENUS PISA: rostrum much developed, stout, formed of 

 two lengthened horns, somewhat conical ; stalk of the ex- 

 ternal antennae nearly on the level of the rostrum. 



FOUR SPINED SEA SPIDER. P. Tetraodon, M. Ed- 

 wards' Crust., vol. 1, p. 305. Leach's Malac. pi. 20. Pen- 

 nant, pi. 8, fig. 15. Much larger than either of the former 

 species, and far more formidable in its appearance. Not 

 common. 



BIBBS' SEA SPIDER. P. Gibbsii, M. Edwards' Crust., 

 vol. 1, p. 307. Leach's Malac, pi. 19. Not uncommon in 

 from 1 or 2 to 20 fathoms of depth, and taken in crab pots. 



