DESCRIPTION OF AN ABNORMAL LOBSTER CHELIPED. 26/ 



one." Further, he calls it a case of "homoeosis" and gives a 

 general consideration of it in relation to Weismannism, etc. 



LITERATURE. 

 Bateson, W. 



'94 Materials for the study of variation, treated with especial regard to dis- 

 continuity in the origin of species. London, xvi + 598 pp. 

 Emmel, V. E. 



'07 Regenerated and abnormal appendages in the lobster. 37th Ann. Rept. 

 Commissioner of Inland Fisheries, Rhode Island, pp. 99-152, pi. 1-9. 

 Faxon, W. 



'81 On some crustacean deformities. Bull. Mus. Comp. Zool., vol. 8, no. 13, 

 PP- 257-274, pis. I, 2. 

 Herrick, F. H. 



'95 The American lobster: A study of its habits and development. Bull. 

 U. S. Fish Comm., 1895, pp. 1-252, pi. A-J, 1-54. 

 Leavitt, R. G. 



'09 An interesting crab's claw. The Guide to Nature, vol. 3, no. 3, pp. 89-91. 

 Verrill, A. E. 



'08 Decapod Crustacea of Bermuda, I. — Brachyura and Anomura. Trans. 

 Conn. Acad. Arts and Sci., vol. 13, pp. 299-474, pi. 9-28. 



Explanation of Abbreviations Used in Figures. 



a., anterior. 



a' ., secondary point of articulation of ischiopodite to meropodite. 



a.p., anterior articular process of meropodite. 



C, carpopodite. 



C+[C'(i? + L)]., carpopodite of abnormal specimen, compounded of the pri- 

 mary and secondary parts. 



d., dorsal. 



d.a., primary (normal) dorsal articulation of ischiopodite to moropodite. 



DL, left primary or normal dactyl. 



D'L, left extra dactyl. 



d.p., primary (normal) dorsal articular process of carpopodite. 



d.p' ., extra (secondary) dorsal articular process of carpopodite. 



D'R., right extra dactyl. 



I, index. 



IL, left primary or normal index. 



l' L, left extra index. 



I'R, right extra index. 



Is, ischiopodite. 



M, line representing position of a plane mirror placed midway between the pri- 

 mary claw and the nearer secondary claw, and normal to the plane in which they 

 lie. 



M', line representing position of a plane mirror placed midway between the 

 extra claws and normal to the plane in which they lie. 



Mer., meropodite. 



p., posterior. 



