92 COLLECTIONS PEOM MKLAITBSTA. 



narrow lamella, wticli on each side becomes rather broader, forming 

 a small lappet of supraoral tentacles. Khinophores rather lateral, far 

 apart, conical, acute at the tips, carinate on the outside, concentri- 

 cally lamellato-striated. Length 27 miUim. 

 Hah. North Australia, Albany Island, 4 fms. 



V6Q. Bornella digitata. 



Adams ^- Reeve, Toy. ' Samarang^ p. 67, pi. 19. fig. 1 ; Alder Sf Han- 

 cock, Trans. Zool. Soc. vol. v. p. 140, pi. 33. figs. 8, 9 ; Bergh in 

 Semper'a Reisen Arch. Philippinen, vol. li. p. 301, pi. 37. figs. 14-19, 

 & pi. 38. figs. 13-22. 



■ Hah. Port Denison, Queensland, 4 fms. (Coppinger). 



I have three specimens before me, which offer certain differences 

 in the number of lobes on the branchial papOlsB and even in the 

 number of the papillae themselves. All these have the four anterior 

 pairs branehiferous, and in each case the two foremost pairs have 

 two branchial tufts at the inner base (in contraction), but the two 

 hindmost pairs exhibit considerable variation. In specimen No. 1 

 both pairs are provided with three tufts, of which the central one is 

 very small. Specimen 2 has three tufts adjoining each of the third 

 pair and two to each of the fourth. Example 3 has three tufts at 

 the base of the left papilla of third pair, and two at the base of the 

 opposite one of the same pair ; of the fourth pair the right papilla 

 is provided with three plumes or tufts and the left with two. 



The annexed table will best illustrate the variation in the lobation 

 of the papillsB : — 



First pair. Second. Third. Fourth. Fifth. Sixth. 



No. 1 3 lobes. 2 -2 1/ 1* 1 



„ 2 3 „ 3 2 2 1 1* 



„ 3 3 „ 2 2 1 1 !• 



The number of the frontal lobes is also very variable. In speci- 

 men No. 1 there are eighteen in both groups, in No. 2 twelve on 

 the left and eleven on the right, and in No. 3 the left consists of 

 sixteen and the right group of twelve. 



Considering these variations, it appears to me very probable that 

 B. arboreseens of Pease is only a variety of this species. The 

 original account by Pease differs considerably from that given by 

 Bergh. The number of lobes on the six pairs of papUlje according 

 to these authors varies, and even the number which are gill-bearing. 



137. Oncidinin (Peronia) punctatum? 



Onchidium punctatum, Qum/ S[ Gaimard, Voy. de V Astrolabe, Zoologie, 

 vol. ii. p. 215. 



Hah. Albany Island and Thursday Island, N. coast of Australia 

 {Goppinger). 



" These are not in pairs, but consist of a single simple papilla on the central 

 dorsal lihe. 



