30 EARLY STAGES OF TEREBRATULINA. 



ft 



and in an early paper entitled " Haemal and Neural regions of Brachiopoda," 1 and later, 

 in a paper on the " Classification of Mollusca, based on the principle of Cephalization," 2 

 urged the intimate relations existing between the Brachiopoda and Polyzoa. With 

 the hopes of learning something about the early stages of one of our native species of 

 Brachiopoda, I visited Eastport, Maine, in the early part of June, 1869, and this com- 

 munication embraces a summary of the incomplete observations there made ; incomplete, 

 as I was unable to secure any data on the embryology of the species. At the outset my 

 microscope proved altogether inadequate to the work before me, though the minute size of 

 the objects examined, coupled with the complicated texture of the shell through which 

 the soft parts had to be observed, rendered the work, at the best, laborious and difficult. 

 In every case, however, the figures given in the accompanying plates are correct tran- 

 scripts of the drawings made from the animal : in no instance is there given any combina- 

 tion of several unfinished sketches to make a more intelligible, or perfect whole. This 

 will explain the absence of detail and completeness in many of the figures presented ; at 

 the same time it is believed that the outlines will be more valuable from the fact that they 

 are not schematic or composite. 



For a clear exposition of the organization of the Brachiopoda, I would refer to the 

 exhaustive memoir of Albany Hancock above referred to, a memoir which justly mer- 

 ited the honor conferred upon him in the award of the Royal medal. 



On the early stages of Terebratulina septentrionalis Couthouy? The specimens upon 

 which the following examinations were made, were dredged in fifteen fathoms of water in 

 the harbor of Eastport, Maine, in the first week of June, 1869. The species occur in 

 great numbers, at various depths, and have also been collected at low tide mark, by Dr. 

 Stimpson and Prof. Verrill. The specimens were found attached to stones brought up in 

 the dredge, and also adhering to the lower valve of adult individuals, generally near the 

 peduncle. An examination of adult individuals showed that while the ovaries in some 

 specimens were empty, in others they were fully charged ; in some the ovaries would be 

 partially empty, in others the ovaries of one side would be nearly empty, while those of 

 the other side would be quite full. Specimens collected by Prof. Verrill in August, were 

 found with eggs ; and eggs were also noticed in specimens less than three sixteenths of an 

 inch in length. The eggs, fig. 1, were generally kidney-shaped, though very irregular 

 as to form and size ; they were spermaceti white in color, and opaque, though having a 

 central area, translucent, and apparently depressed. In general outline they suggest the 

 kidney-shaped eggs of Fredericella. No intermediate stage was observed between the 

 ovarian egg and the stage represented in fig. 2. This form recalled the general propor- 

 tions of Argiope and Megerlia, in being transversely oval, in having the hinge margin 

 wide and straight, and in the presence of a proportionately wide foramen. This stage was 

 exceedingly minute, and only two individuals were discovered ; they were attached to the 

 rock, resting on the broad hinge area ; nothing could be traced of the structure, except an 

 appearance of granular contents, as indicated in the figure ; the shell showed nothing of 



1 Proceedings Boston Society Natural History, vol. IX. can Naturalist, Sept. no., vol. Ill, 1869. Since reprinted in 



1862. American Journal of Science and Arts for Jan., 1870. 



'Proceedings Essex Institute, Salem, vol. IX, part 6 The general results were communicated at the 18tli An- 

 1865. Also reprinted in American Journal Science and nual Meeting of the American Association for the Advance- 

 Arts, vol. XLII, no. 124. 1866. ment of Science, Aug., 1869. 



' A brief resume of this paper was published in the Amer- 



