ORTMANN : TERTIARY INVERTEBRATES. 249 



Record of specimens: Upper Rio Chalia, 4 sp. (on a specimen of Tnr- 

 ritella ambulacrum}. 



Distribution: Recent: Tierra del Fuego, Eastern Patagonian, Chili, 

 Peru (Darw.). 



Fam. BALANID& Darw. 



Gen. BALANUS List. 

 176. BALANUS cf. PSITTACUS (Molina). 



PI. XXXVIII, Fig. 2. 



1854 B. p. Darwin, Mon. Cirrip. Balan., p. 206, pi. 2, f. 3. 

 1887 B. p. var. minor Philippi, Tert. Quart. Verst. Chiles, p. 223, pi. 51, 



f. 4, 5- 



1896 B. p. var. minor Moericke, in: N. Jahrb. Miner., etc., Beil. Bd. 10, 



P- 59i- 



1897 B. p. Weltner, in: Arch. f. Naturg., v. i, p. 261. 



"... Orifice hexagonal. Scutum with the articular ridge very small, 

 confluent with the very prominent adductor ridge, forming a tubular 

 cavity, which extends up to the apex of the valve. Tergum with apex 

 produced, needle-like, purple ; spur placed at less than its own width from 

 the basi-scutal angle." (Darwin.) 



Remarks: From the base of the Patagonian beds at Lake Pueyrredon 

 we possess two specimens of a large Balanus, which seems to be dis- 

 tinct from B. varians. The one measures : Height, 52 mm, diameter, at 

 base, 40 mm; the other: height, 48 mm, diameter, 51 mm. Both are 

 poorly preserved, and do not possess opercular valves. The parietes are 

 porous, and the orifice is subhexagonal, which would correspond, together 

 with the large size, to B. psittacus. This view is supported in some 

 degree by the fact that this species has been recorded and figured by 

 Philippi from the Navidad beds of Chili, and our specimens agree closely 

 with the figure 4 of Philippi. Philippi figures also (fig. 5) the scutum, 

 which corresponds to that of this species (Darwin, pi. 2, f. 3<z), and so it 

 seems probable that this large Balanus really belongs to the recent B. 

 psittaciis, although this assumption needs further confirmation through the 

 discovery in the fossil form of the very characteristic tergum. 



From Cape Fairweather we possess two specimens, one upon the other, 

 of a Balanus that is considerably larger than the common form, although 



