2 Brack. 
BRACHIOPODA. 
12. Shipley, A. E. Ueber das Nervensystem der Argiope. Zool. Anz. 
viii. pp. 25 & 26. 
13. Verrill, A. E. Third Catalogue of JSIollusca , recently added to 
the Fauna of the New England Coast and the adjacent parts of the 
Atlantic. Tr. Conn. Ac. vi. pp. 395-452, pis. xlii.-xliv. [ Brachio• 
poda , pp. 445 & 446]. 
Anatomy and Physiology. 
Lankester (8) considers the Sipunculoidea , Brachiopodci, and Polyzoa as 
equivalent branches of a newly-constituted phylum “ Podaxonia” the 
arms of the Brachiopod being regarded as homologous with the Polyzoan 
lophophore. 
Blochmann (1) substantiates Hancock’s statement that the heart of 
Terebratulina and Waldheimia is a contractile organ. In the former it 
pulsates 30 times in 30-40 seconds. It contains branched muscle-cells. 
The veins described by Hancock are lacunae between the two layers of 
the mesentery ; his “ afferent brachial canal ” is the supra-oesophageal 
arm-nerve. Furthermore, the plexuses described by Hancock are 
branched connective tissue-cells, not vessels. A brachial vessel, sending 
branches to the cirri, runs behind the oesophagus and gives off branches 
which open into a sinus surrounding the oesophagus. Heart and vessels 
have practically the same distribution in seven species examined, but are 
somewhat different in Crania anomala. Here there are two larger and 
several smaller cavities at the posterior end of the so-called “ veins,” of 
very simple structure ; there are also differences in the brachial vascular 
system. The heart in Argiope, though not mentioned by Schulgin and 
Shipley, is easy to find, and occupies the same position as in other forms. 
In Argiope neapolitana there are two such hearts (= the supra-cesopha- 
geal ganglia of Schulgin). In Crania there are two pairs of straight, 
three of oblique muscles, and one unpaired median. The mantle margin 
has no bristles, and there is a median posterior anus. The nervous 
system is, on the whole, correctly depicted by Van Bemmelen. Crania 
has no proper supra-oesophageal ganglion, but only a slender commissure; 
lateral commissures were not found. 
The upper shell of Crania is traversed by pores which ramify into very 
fine apertures on the outer surface ; the ventral valve is only perforated 
where there are no muscular insertions; at these points the shell is 
covered by calcified cartilage. The outer layer of the mantle is composed 
of similar substance, with a layer of spongy tissue between it and the 
shell; the other surface is clothed by ciliated epithelium. The inner 
layer of the mantle is occupied by the genital organs. There are three 
principal pairs of muscles ; the anterior and posterior are adductors, the 
third is oblique, and serves to thrust the free valve forwards or side¬ 
ways ; the arms are sustained by other muscles. The cirri are carti¬ 
laginous tubes, covered externally by ciliated epithelium ; internally they 
are lined by an epithelium continuous with that of the brachial canals. 
Respiration is effected by the mantle, and there is no special circulatory 
