ACADEMY OF NATURAL SCIENCES. 15 



this is the reason why I offer a new and complete description of the Scutella 

 interlineata, from specimens procured in situ. As was suggested by Mr. W: P. 

 Blake, the rocks bearing these fossils are found a few miles southward, north of 

 the boundary line between San Mateo and San Francisco Counties, where the 

 scutella? stick out from conglomeratic sandstones, which Mr. Gabb considers as 

 belonging to the pliocene or post-pliocene formation ; we find them in a fine state 

 of preservation, with their spines retained. 



The S. interlineata is figured in the Railroad Reports ; see vol. V, Geologi- 

 cal Report, plate IV, fig. 30 ; aud for Mr. Blake's remarks and Mr. Stimpson's 

 description, the same Report, chap. XII, p. 153. 



Dr. J. Blake made some remarks on specimens, presented by 

 him, of infusoria, found in the sand-hills, south of Point Lobos, and 

 which form a kind of concretions, fixing the sand in its place. 



Dr. Ayres made the following remarks in relation to the genus 



NOTORHYNCHTJS : 



This genus was defined by me in 1855 (Proc. Cal. Acad. Nat. Sci., vol. I, p. 

 72) to include a species occurring in the Bay of San Francisco. In 1858 

 Girard refers to the species (P. R. R. Rep., vol. X, p. 367) under the generic 

 name Heptancbus, of which he considers Notorhynchus a synonym. In 1861, 

 Mr. Gill refers it to Rafincsque's genus Heptranchias. (Annals of the Lye. 

 Nat. Hist., N. Y., vol. VIII, Dec.) In a more recent paper (Proc. Acad. Nat. 

 Sci., Phil., Oct., 1862) Mr. Gill restores my species to the name under which it 

 was originally described. He says : " This generic name of Notorhyxchus 

 was proposed by Dr. Ayres under a misapprehension." My " misapprehen- 

 sion " was that I regarded the species as the type of a new genus; a conclusion 

 at which Mr. Gill himself has, after several changes, also arrived. He gives as 

 a synonym of Notorhynchus only " Heptanchus, Sp. Muller and Henle, Gray, 

 Girard, Gill," whereas it is necessary to include also " Heptranchias, Gill," as 

 above indicated. 



I may remark that the description given by Mr. Gill of the teeth of Notorhyn- 

 cus maculatus, (Proc. Acad. Nat. Sci., Phil., Oct., 1862, p. 495) will not bear 

 examination. It represents the individual specimen on which it was founded ; 

 but the species is quite common here, and I find that the number and the forms 

 of the teeth vary so much, that my original description, which Mr. Gill says is 

 "equally applicable to any species of the family," is fully as close as nature will 

 allow us to draw. I am at a loss to understand how it is possible for him to 

 refer the jaws of a shark, collected at a point so far removed from us as Nis- 

 qually, to my species, when my description is so extremely indefinite. 



Professor Whitney gave an account of an interesting collection 

 of Japanese minerals and fossils, in the possession of J. H. Van 

 Reed, Esq., of this city. 



