INVERTEBBATE ANIMALS. 69 



Group 171.— Family PALINURID^. The Spiny Lobsters 

 are undoubtedly amongst the most handsome of the 

 Macroura ; but the group is chiefly interesting from 

 the fact that the Glassy-Crabs, Phyllosoma, till recently 

 supposed to be included in the Stomapoda, are now 

 recognised as larval forms of the Palinuridce. In 

 Astacus and Ilomarus, the young, from the time when 

 they are very small, are said closely to resemble the 

 adult. If this be true, the affinity between the Lobsters 

 and the Spiny Lobsters is probably simply a mor- 

 phological one, and points of great interest may be 

 expected to occur during future investigations of the 

 physiological character of the Spiny Lobsters. The 

 species are widely distributed, and are found on rocky 

 coasts. 

 Estimated number of species: recent, 13; British, 1. 



IT Examples of P. guttatus, P. Lalandii, P. longi- 

 manus, dc, and of Phyllosoma. 



Group 172.-Families SCYLLARID^ and GALATHEIDiE. 

 The Broad-lobsters, ScyllaridcB, derive much of the pecu- 

 liarity of their form from an extraordinary modification 

 of the outer pair of antennae, which in this family are 

 developed into broad flat plates, sometimes strongly 

 toothed on the margin and probably serving for shovels 

 in excavating holes in the sea-bottom, in which the 

 animals take shelter whilst watching for their prey. 



The Plated-lobsters, Galatheidce, resemble the pre- 

 ceding in habit. Mr. Couch observes, with reference to 

 Galathea strigosa, "It is very remarkable to witness the 

 accuracy with which they will dart backward for several 

 feet into a hole very little larger than themselves ; this 

 I have often seen them do, and always with precision." 



