338 INVERTEBRATA OF MASSACHUSETTS. 



Genus ANTHURA. 



A. GRACILIS, Leach; Lam.; Latk. ; Desm.; Consirf., 291, pi. 46, f. 13. 

 Milne-Edw.; Hist. A'at. des Crust., pi. 31, f. 3, 4. 



Genus LIMNORIA. 



L. Te'rebRANS, Leach; Lin. Trans., xi. 370. Latr. ; Desm.; Cold- 

 stream ; Edin. JVew Philos. Journ., xvi. (1834), 316, pi. C, f. 1 - 18. Thompson ; 

 ibid., Jan. 1835. 



A very small animal which burrows in timber immersed in the 

 sea, making small furrows, and, by its numbers, often doing con- 

 siderable damage. 



Genus STEN0S(!)MA. 

 S. IRRORa'ta, Say ; Journ. Mad. JVat. Sc, i. 423. 



Probably the same as Oniscus entomon, Lin. ; Cymothoa ento- 

 mon, Fabr. ; Idotea entomon, Latr. ; Desm., &c. 



The animal to which I here refer, I suppose to be the same 

 which Mr. Say had in view. It is extremely common, clinging 

 to the long, narrow leaves of Zostera marina. It becomes nearly 

 an inch in length, but is usually much shorter. Its colors are sea- 

 green, variegated with brown and straw-color. It is often mot- 

 tled or margined with the latter color, and might lead one to sus- 

 pect there were many species assembled. 



There are two or three other species which I cannot yet refer 

 to any description. 



Genus CYMOTHOA. 



C CESTRUM, Fabr.; Syst., ii. 505. Latr.; Leach; Desm.; Consid., 

 309, pi. 47, f. 6, 7. Griffith's Cuv. (Crust.) pi. 8, f. 1. 



C. (jEga) EMARGINA'TA, Leach; Diet, des Sc.JYat.jXn.SiO. Desm.; 

 Consid., S/-C., 305, pi. 47, f. 4, 5. Griffith's Cuv., (Crust.) xii. pi. 8, f. 3. 



C. (^ga) . Another species. 



C. (Anilo'cera) . One species. 



C. (IcHTHYo'PHiLUs) . One species. 



These all inhabit the mouths and gills of fishes. 



