40 A. S. PACKARD, JR., ON THE ANATOMY 



developed tails. We introduce a figure of those of a species of Lepas collected at 

 Penikese, an island at the mouth of Buzzard's Bay. The head is broad and flat, plainly 

 sinuous seen sidewise, the centre being filled with granules. The spermatocysts (plate 3, 

 fig. 5) are spherical, usually containing five spermatozoa. 



The tubules of the testis of Limulus are yellowish ; this color is due to the presence of 

 numerous yellow jiigment granules. Fig. 4« represents the epithelial tissue forming 

 the walls of the follicles (fig. 4). The spermatocysts (fig. id) are spherical, containing 

 four immature spermatozoa, while the earlier condition of the same is seen at fig. 4&, 

 where the sperm-cells are nucleated. 



We introduce for comparison drawings (fig. 6) of the spermatocysts of a decapod 

 Crustacean {Lihinia canallculata), the spermatozoa (fig. G/) being tailless and nucleated. 

 Certain larger cells have a large nucleus, with a small nucleolus ; the nature of these cells 

 we do not understand. 



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LocKwooD. The Horse-foot Crab. By Rev. S. Lockwood. American Naturalist, iv, July, 1S70. 



Packard. The Embryology of Limulus polj-^ihemus. By A. S. Packard, Jr. American Naturalist, 

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On the Embryology of Limulus polyjihemus. By A. S. Packard, Jr. Proceedings American 



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pp. 754-756. Feb., 1871. 



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Packard, Jr. Amer. Nat., vii, pp. 675-678. Nov., 1873. Proceedings Amer. Assoc. Adv. Science. Port- 

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On the Development of tlie Nervous System in Limulus. By A. S. Packard, Jr. Amer. Nat., 



IX, pp. 422-424. July, 1875. 



On an Undescribed Organ in Limulus, supposed to be renal in its nature. By A. S. Packard, Jr. 



Amer. Nat., ix, pp. 511-514. Sept., 1875. 



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Van Beneden. De la place qui les Limules doivent occuper dans la Classification des Arthropodes 

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