ORTMANN : TERTIARY INVERTEBRATES. 
53 
Remarks: Our single specimen is very badly crushed on the under side, 
but fortunately there are preserved a number of spines : these are short, 
thin and sharply acuminate, with fine longitudinal striations. The form 
of the actinostome is unknown. 
Hyp. patagonicus (sic!) mentioned by v. Ihering (1897 a > P- 336) appar- 
ently does not belong to this species, since he says that individuals from 
the Bay of San Jorge in his possession differ in the number of tubercles in 
the interambulacra. Possibly they belong to the next species. 
Record of specimens : San Julian, Darwin Station, 1 sp. 
Distribution : 1 So far only known from San Julian (d’Orb.). 
Affinities: The chief character of this genus is found (according to 
Desor) in the primary tubercles of the ambulacra, which are, on the actinal 
side, about as large as those of the interambulacra, but decrease rapidly in 
size toward the abactinal system, becoming much smaller than the latter. 
Although this character does not seem to warrant the generic separation 
of this species from Echinus , it is not observed in any other species, and 
so it is impossible to point out any particular relations to any known spe- 
cies of Echinus. 
Gen. TOXOPNEUSTES Ag. 
3. Toxopneustes precursor Ortmann. 
PL XI, Fig. 3“' 6 . 
? 1897 Hypechinus patagonicus v. Ihering, in: Rev. Mus. Paul., v. 2, p. 
336 (non H. patagonensis d’Orb.). 
1900 Toxopneustes precursor Ortmann, in: Amer. Journ. Sci., v. 10, p. 
369 - 
Test suborbicular, slightly subpentagonal, subconical. Ambulacral and 
interambulacral spaces with 4-8 vertical rows of tubercles, of subequal 
size, those of the ambulacral spaces being a little smaller. Poriferous zone 
moderately broad, about half as broad as the median part of the ambu- 
lacrum. The latter with 4 vertical rows of tubercles, the two outermost 
the largest, and only these extending to the abactinal system. Pores in 
three pairs, the two outer vertical rows of pores placed slightly closer 
together, and separated from the inner row by a small tubercle, these 
1 Under this head I shall give the data of distribution previously reported. 
