1879.] NATURAL SCIENCES OP PHILADELPHIA. 95 



TRITONIIDiE. 



The genus Tritonia was established by Cuvier as early as 1798, 

 but may have been at first 1 hardly separable from the forms subse- 

 quently named Dendronotus, A. and H. 



Cuvier gave no type of the genus. Lamarck soon afterward 

 (1801) adopted the name of Cuvier,' 2 but used as example the 

 Doris clavigera of Miiller, which has since become the type of the 

 genus Triopa. Thus the genus must really take date from the 

 later anatomical publication of Cuvier in 1802. 3 The genus is not 

 properly characterized here, and contains tlieD. clavigera ('= Tri- 

 opa), the D. cervina (=Dendronotus), the D.coronata (=Doto), the 

 D. arborescens (=Dendronotus), and the D. frondosa (='Tritonia 

 Hombergi), besides a form which Cuvier regarded as probably 

 new, the Tritonia Hombergi, which he seems to establish as the 

 type of the genus, especially in the first edition of the Rogue 

 Animale, 4 and this has since been regarded as the typical form by 

 all later authors. 



Except that some new species of the genus were described", 

 nearly nothing since Cuvier was known of these animals until 

 the anatomical examination of the Trit. tethydea, by Delle Chiaje, 

 1824, 5 and especially until the excellent publications of Alder and 

 Hancock in 1855. 6 



The genus has by different authors been classed with other genera 

 in different wa} r s ; as a family Tritoniacea (Menke, Philippi, Forbes, 

 andLoven); Tritoniae (Fer., Rang) ; Tritoniadee (Johnston) ; Tri- 

 tonidee (d'Orb.) ; but all the arrangements have been quite unna- 

 tural. Alder and Hancock first (1855) formed a natural group of 

 Triton iadiee, 7 only including the genus Tritonia, and this family 

 was soon after (1857) adopted by Gray. 8 



1 Tabl. Eltim. an vi. (1798), p. 387. " Le nombre des tentacules qui 

 entourcnt la bouche varie cle deux a knit." Cuvier, 1. c. 

 * 2 Lamarck, Syst. des animaux sans vert, an ix. (1801), p. 65. 



3 Cuvier, Mem. sur le genre Tritonia, Ann. du Museum, 1, 1802, pp. 480- 

 496, PI. XXXI.-XXXII. 



4 Cuvier, Regne Animale, ii. p. 391, 1817. 



5 Delle Chiaje, Mem. sulle storia degli an. s vert. iv. 1S29. Tav. lxii. ed. 

 2, V. p. 74. 



6 Alder and Hanc, Monogr. of the Brit. Nudibr. Moll., Part VII. 1855. 

 fam. 2, PI. I.-II. 



' Alder and Hanc, 1. c. Part VII. 1855, app. p. xx. 

 8 Gray's Guide, i. 1857, p. 218. 



