6,")8 siK c. ELIOT ON NUDiBRANCHS [June 19, 



T. anceps Bergh (Bull, of Museum of Comparative Zoology, 

 Harvard, 1890, p. 169) is a doubtful form omitted by Bergli in 

 subsequent lists of the genus, and perhaps akin to Atagema. 

 T. hispida is also regarded by Bergh as doubtful, but, so far as 

 one can judge from the plates (Opisth. der Sammlung Plate, 

 p. 527, pis. XXX. & xxxi.), seems to possess most of the characters 

 of the genus. 



It is sometimes difficult to distinguish the external characters 

 of Thordisa and Trippa verbally, for some species of Tkordisa 

 have soft tubercles which bear secondary papillae or filaments. 

 But whereas the typical Thordisa is rather flat and covered with 

 soft, elongate papilke, the typical Trippa is spongy, though often 

 full of spicules, and bears large, irregularly compound tubercles, 

 with pits between them. 



Trippa ornata Bergh. 



(Bergh in Semper's Reisen, Heft xii. p. 543, and Heft xvii. 



p. 905. Id., Siboga-Expeditie, Opisthobr. p. 129. 

 Cf. Kelaart, Doris intecta, 1. c. I. p. 302.) 



The original specimen described by Bergh in 1877 was 

 reddish-brown with a yellowish median longitudinal band. In 

 another specimen (1890) he found a white longitudinal band (not, 

 however, marked in the figure, Semper's Reisen, Heft xvii. 

 pi. Ixxxiv. fig. 7), and suggested that the animal might be Kelaart's 

 Doris intecta. This suggestion is rendered even more probable 

 by the description and figures in the ' Siboga ' Expedition volume. 



Kelaart's figure represents a reddish-brown, tuberculate Dorid 

 with a white line extending from the branchiae to the rhinophores. 

 The only objection to identifying it with Trippa ornata is that 

 it is said to have long oral tentacles, whereas the accounts of the 

 preserved specimens suggest that the tentacles are rudimentary. 

 As Doris intecta is said to be very common at Trincomalee in low 

 water during September and October, the identitj^ may perhaps 

 be decided by an examination of further specimens. 



Trippa luteola (Kelaart). (Plate XLII. fig. 4.) 



{Thordisa caudata Farran, 1. c. p. 341. Doris luteola Kelaart, 

 1. c. I. p. 299.) 



Two specimens from the reef at Tamatave, Madagascar, given 

 me by Prof. Yoltzkow. A note with the specimens says : " Saum 

 citronen galb. Flihler schwarz. Kieme schwarz." Through 

 the kindness of Prof. Herdman, I have also been able to examine 

 the single type specimen of Thordisa caudata in the Museum of 

 Liverpool Univeisity. All three specimens undoubtedly belong 

 to the same species. 



The specimens from Madagascar are much bent, but if straight- 

 ened out would be 35-40 mm. long and 20-25 broad. The 

 colour is a, rathei- dirty white. The back is in most parts covered 

 with flat tubercles of various sizes, generally bearing secondary 



