246 

 Cryptophrys Rathbun. 



1893. Cryptoplirys Rathbun. Proc. U.S. Nat. Mus., v. 16, p. 250. 



Only one species is known, Cryptophrys coiichariiin Rathbun, 1. c. ^), which inhabits the 

 coast of Lower Cah'fornia and lives in the mantle-cavity of Mya arenaria and Cardita. 



Xanthasia White. 

 Literature : Alcock, Jouni. As. Soc. Bengal, v. 69, prt 2, 1900, p. 340 — 341. 



The typical species is the very characteristic Xanthasia iimrigcra White; its records in 

 literature are enumerated by Alcock, 1. c. lts original locality are the Philippines, but afterwards 

 it has been recorded from the Fiji Islands, New Caledonia, Mozambique, Mergui Archipelago, 

 Andamans, New Guinea and Australia. 



A second species is Xanthasia lüJiitci de Man -) from the Mergui Archipelago. Like 

 the typical form it inhabits the mantle-cavity of Lamellibfanchs ; the lateral margins of the 

 carapace are not thin, but thickened, they are separated from the likewise thickened posterior 

 margin, and the tubercle in the middle of the carapace is not shaped like a mushroom and ill-defined. 



Dürckheimia de Man. 



1889. Dürckheimia (Rüppell in M.S.) de Man. Zool. Jahrb., Syst., Bd 4, p. 442. 



The genus has been founded on Dürckheimia carinipes de Man, from the Red Sea. 

 It presents a rounded, elevated ridge parting from the middle of the posterior margin of the 

 carapace, but disappearing in the anterior third of the carapace. In a second species, Dürck- 

 heimia caeca Burger '^) from the Philippines, this median ridge is thinner, crest-Iike, and continued 

 forward to the deep notch in the anterior margin of the carapace. 



Scleroplax Rathbun. 

 1893. Scleroplax Rathbun. Proc. U.S. Nat. Mus., v. 16, p. 250. 



The only species is Scleroplax graiuilaia Rathbun, 1. c, p. 251, from California *). 



Raphonotus Rathbun. 



185 1. Fabia Dana. Am. Journ. Sc. (2), v. 12, p. 290 (praeocc). 

 1897. Raphonolits Rathbun. Proc. Biel. Soc. Washington, v. 11, p. 166. 



This genus again contains only a single species, Fabia stihqiiadrata Dana ^) from Oregon 



i) See also Holmes, Occas. Pap. Californ. Ac. Sc, v. 7, 1900, p. 96; Rathbun, Harriman Alaska Exp., v. 10, 1904, p. iSS; 

 Weymuuth, Leiand Stanford Jr. Univ. PubL, n" 4, 1910, p. 60. 



2) Journ. Linn. Soc. London, v. 22, 1888, p. 106, pi. 7, f. i. 



3) Zool. Jahrb., Syst., Bd. 8, 1895, p. 385, pi. 9, f. 33, pi. 10, f. 31. 



4) See also Holmes, Occas. Pap. Californ. Ac. Sc, v. 7, 1900, p. 94; Rathbun, Harriman Alaska Exp., v. 10, 1904, p. 1S8; 

 Weymoüth, Leiand Stanford Jr. Univ. PubL, n" 4, 1910, p. 59, textfig. 8. 



5) Proc. Ac. Nat. Sc. Philadelphia, 1851, p. 253; U. S. Expl. Exp., Crust., 1852, p. 383, pi. 24, f. 5; Holmes, (part.), Occas. 

 Pap. Californ. Ac. Sc, v. 7, 1900, p. 87; Rapl!o?tottis subquadratus Rathbun, Harriman Alaska Exp., v. 10, 1904, p. 186; Weymoüth, 

 Leiand Stanford Jr. Univ. PubL, n» 4, 1910, p. 55, textfig. 2. Holmes, according to Miss Rathbun, confounded with R. suliquadiattis 

 another apparently new species, which is called A'. lowci. Kaf/ionotus is very common in the mantle cavity of the common mussel 

 (^AJytilus eJulis) and in the folds of Lncapina cicnulata (a Gastropod allied to Fissurclla). 



98 



