THE CRUSTACEA OF NEW JERSEY. 333 



Genus HO MAR US Weber. 

 The Lobsters. 



Homarus Weber, Nomenclator EntomoL, 1795, p. 94. Type Astacus marinus 

 Fabricius, first species. (Virtually designated [as Cancer gammarus 

 Linnjeus] by M. J. Rathbun, Proc. Biol. Soc. Wash., XVII, 1904, p. 170.) 



Carapace nearly cylindrical, and rostrum armed on each side 

 with three or four teeth. Thorax with last joint immovably 

 connected wnth preceding one. Abdomen nearly cyclindrical, 

 segments ending laterally in large flattened triangular process- 

 Terminal abdominal segment with tooth on each side near end. 

 Telson with outer lamina divided transversely, about a third 

 from end, with distinct movable joint. External antennae sit- 

 uated above and to outer side of internal pair, scale dentiform, 

 dilated on inner side and scarcely covers penultimate joint of 

 peduncle. Internal antennse wath peduncle nearly long as 

 that of external. Eyes subglobose, not broader than foot-stalks. 

 External foot- jaws pediform, reach forwards beyond peduncles 

 of antennse. Anterior legs very robust, unequal, larger with 

 fingers strongly tuberculated on grasping edge and smaller 

 merely toothed. Second and third pairs of legs didactyle, and 

 fourth and fifth pairs monodactyle. 



Species three, and the single form known from our shores 

 very large, prolific, and greatly valued as food. 



The generic name of this animal has been the subject of much 

 controversy. Homarus is accepted here in accord with pre- 

 vailing opinion, and the name Astacus is allowed for the craw- 

 fishes. Astacus dates from Gronow in 1764, if polynomia- 

 lists are accepted, or from Fabricius in 1792, if binomialists 

 only are used. In any case Cancer astacus Linnreus is the type 

 according to the law of tautonomy. According to Faxon, in 

 1898, its first designation wath a type species was by Latreille, 

 in 1810. Ortmann claims a prior designation, with different 

 results, though his suggestions would be invalid if considered 

 from the point of view of tautonomy. Homarus is used as a 

 nomen nudum by Fabricius in 1796, in the index to his supple- 

 ment. 



