1886. } Zoology. 979 
carapax of crabs and lobsters represents the coalesced terga of 
all the cephalic and thoracic segments, and a line crossing it is 
‘ pointed out as the suture dividing the head from the thorax—the 
cervical suture. This view is wholly erroneous and has arisen 
from an attempt to trace homologies where none exist. Dr. 
Howard Ayers (Bulletin Essex Institute, Vol xvii, pp. 49-59, pls. 
U-11, 1886) has recently restated the problem and the evidence 
to show that the carapax is in reality to be regarded as the coal- 
esced terga of the antennal and mandibulary segments, and that 
the “cervical suture” merely indicates the line between them. 
His presentation of the case should be conclusive. He further 
shows that the parts regarded by Milne-Edwards as episterna 
are in reality portions of the sternum cut off by the appearance of 
false sutures, 
Fe ee Seer 
DEVELOPMENT OF PHyLiopops.—Claus, in the last Heft of the 
sixth volume of the Arbeiten zool. Inst., Wien, gives an account, 
illustrated with twelve plates, of the structure and development of 
the Phyllopod genera Branchipus and Artemia, which supple- 
ments his former paper published in Gottingen, 1873. He dis- 
cusses the segmentation and development of the body during 
metamorphosis, the segmentation of the mesoderm and the differ- 
entiation of the ectodermal and mesodermal organs, the formation 
of regions and the number of segments, integument, connective 
tissue and fat bodies, muscles, nervous system and sense organs 
(including the median and lateral eyes), the alimentary and excre- 
tory organs, heart, circulation and respiration, and the sexual or- 
gans, thus giving a monographic treatment of the development of 
the group. 
_ THE Rips or SPHENODON (Hatteria).—Cope! has shown that 
in some of the Pelycosauria the capitulum of the two-headed ribs 
4S attached to the intercentrum. 
_, The question arose immediately: Is it not probable that the 
living Sphenodon with so many characters. common to the 
Permian Pelycosauria shows the same condition ? 
._ The ribs of Sphenodon are described by Owen, Ginther and 
| brecht, None of these authors speak about ribs connected with 
_ the intercentrum (hypapophysis), but they have observed two- 
headed ribs in the cervicals. : 
_ Owen? says: “The fourth vertebra has a short pleurapophysis 
On each side with a bifurcate proximal end articulated by a broad 
tubercle to the diapophysis and by a slender neck and head to a 
Cleat aaa 
Cope, E. D, Description of Extinct Batrachia and Reptilia from the Permian 
tons of Texas. Palzontol. Bull. No. 29, p. 518. Amer. Philos. Soc., April 5, 
The Relations between the Theromorphous Reptiles and the Monotreme Mam- 
nee Proc. Amer. Assoc. Advanc., Sc., Vol. xxx, Philadelphia meeting, Sep- 
aber, 1884. : 
Roya ope ptive Catalogue of the Osteological Series contained in the Museum of the 
College of Surgeons of England. Vol. 1. London, 1853, p. 142. 
