BRAOHIOPODA. 183 
Terehratula monstruosa, Scacchi, is distinct from M. truncata, h. ; and T. 
luniferay Philippi, is a variety of monstruosa. Seguenza, Bull. mal. Ital. iii, 
pp. 147, 148. 
Argiope. Orthis hijida, Costa, is a variety of A. neapolitana. Seguenza, 
1. c. p. 147. 
Lingula pyramidata^ Stimps., studied on the shores of North Carolina by 
E. S. Morse. It is found in a sand-shoal at low-water mark, buried just be- 
low the surface of the sand. The peduncle is encased in a sand-tube, differ- 
ing in no respect from the sand-tube of neighbouring Annelides, and has been 
found broken and repaired in many cases. The animal has the power of 
moving over the sand by the sliding motion of the two valves, using at the 
same time the fringes of the setae, which swung promptly back and forth like 
a galley of oars. P. Bost. Soc. June 1, 1870 (Am. J. Sc, 1. pp. 100-104). 
TUNICATA. 
Ascidias simplices. 
C. Kupffer has observed the development of Ascidia canina, 
Miill., which is common on the Zoster a marina at Kiel. 
Before his researches he was rather sceptical concerning the 
homology of the larval organs in the Ascidiidie with those of the 
Vertebrata, but now comes to the conclusion that this homology 
exists, and certainly in a higher degree in the Ascidia canina, 
observed by himself, than in A. mamillata, observed by Kowa- 
lewsky, and that this homology is shown as well by the genesis 
as by the relative position of the organs. The most striking ex- 
amples are, according to him : — 1. The chorda originating from 
a double row of internal cells, and transforming itself into a 
hyaline, cartilaginous, elastic axis, with an envelope of cellular 
structure. 2. The position of the central nervous system above, 
and that of the intestinal tube below this chorda. 3. The ge- 
nesis and form of the nervous system itself. 4. The intimate 
connexion of the branchial sac and the intestinal tube, both 
making their first appearance as one common organ. 5. The 
relations of the muscles to the envelope of the chorda. Some 
peculiarities, on the contrary, of the Ascidise, in their deve- 
lopment, disagreeing with that of the Vertebrata, are the 
retardation and very low degree of the circulatory system and 
the conjunctive or mucous membranes — and, further, the very 
strange gelatinous envelope of the whole larva, containing 
amoeboid cells, and originating from the peripheric cellular 
stratum of the yelk existing before the fecundation. 
The author proceeds to trace the metamorphosis from the 
larva to the full-grown Ascidia, He states, among other par- 
ticulars, that the endostyle of the Ascidia is formed by the 
original epithelium of the branchial sac in a ventral furrow of 
the larva, and adopts, therefore, also the determination of 
