798 



THE AMERICAN NATURALIST [Vol. XLI 



In the Bulletin Amer. Mus. Nat. Hist. (XXIII, 1907), Mr. L. 

 Hussakof describes a fossil surgeon-fish from Antigua Island, West 

 Indies, in rocks supposed to be of Eocene Age, The species, repre- 

 sented by a very complete skeleton is named Zebrasoma deani. This 

 species is the first of the family of Hepatidae (Teuthidae) found in 

 America, and it is the only fossil species of the genus Zebrasoma. The 

 pertinence of the species to the living genus Zebrasoma may be ques- 

 tioned. The first dorsal spine is the longest and seems semi-detached. 

 In Zebrasoma the first is much shorter than the others. The soft fins 

 in Zebrasoma are very high. In Z. deani, they are quite low. The 

 caudal peduncle is slenderer in Z. deani and the tail much more Avidely 

 forkcMl than in any species of Zebrasoma. The number of vert(>bra 

 (8 + 11 = 19) is' fewer than in living Hepatidae (22). The caudal 

 spine possibly existed, but if so, it is lost in this spec-imen. 



If the fish is to be referred to an existing genus, CaHicanthus with 

 a slender tail and a widely forked fin, with the first of Ihe five dorsal 

 spines enlarged and with the vertical fins low, is near(>r to the species 

 than is Zebrasoma. The profile in Callicanthus is curved in Z. 



deani, it is very straight. 



In the Bulletin de la Societe Beige de (Jcologic (XXI, l!)()7). Dr. 

 Louis Dollo eii(l',>avoiN 1„ show that tlu^ pt vctodoiU fi^h.-., Mipposcd to 

 be fossil chi.na<Toi<l., ivallv Ik Ion- to th;- on!, v <.f An hn.. li.vs. He 

 further comhidr. that the chiinarra. are .sp.ria IIamI ,o.-hho<lonts, 



Dr. Dollo further adds that "lh(- idra of th(> 1 rrr v« rsibihty ol' Evolu- 



more shown its iitihty, c l^e oiu- wouhl !).■ K d to i.iaiir aiii that .pecialized 



order to b:com;- again siKviahze.i in 1h.- same or in different direction." 



Dwri) Starr Jordax. 



Notes on the Structure of Insects.-- .1 Shuhi oj thr (Untmion IIoii.tr- 



