REPORT ON THE BRACHIOPOUA. 7 



The animal of the same species of Brachiopocl is, moreover, capable of existing at . 

 difl'crent depths without any observable modification in shape and character. It has 

 also been clearly ascertained that tlie Brachiopoda, although widely distributed, are very 

 much localised, and usually occur in great numbers in their, respective haunts. If we 

 examine the nature of the sea-bottom from which the Challenger specimens were 

 obtained, we find that they Avere dredged eleven times from sea-bottoms composed of 

 rock and clay, twice from stones and gravel, three times from sand, and twelve times 

 from soft bottoms composed of mud, globigerina, or grey ooze ; but, as previously 

 stated, as a rule, they prefer rocky bottoms and coral reefs. Brachiopoda are also found 

 clustering together in vast numbers, adhering to one another liy their peduncles, or 

 massed together, one above the other, till they sometimes form a living aggregation of 

 considerable breadth and thickness, as is the case with Discina lameUosa, D. IcBvis, and 

 other species. The young shell is even very often found attached to the peduncle of 

 its neighbour, but according to Morse and other zoologists who have made the embryology 

 of the class their special study, the fry before becoming attached swims, or whirls head 

 foremost by means of the vibratile cilia covering the body. Lingula and Glottidia, it 

 is well known, abound in particular haunts, and live at about half-tide mark, and partly 

 buried in mud. at depths varying from 3 or 4 inches from the surface to 7, 10, 17, and 

 60 fathoms ; but the ranges of depth of six or seven of the species are still unknown.^ 



Observations connected with the living animal are especially needed, Isut these can 

 only be made when the animal is brought up alive and placed for some time in jars of 

 sea-water. 



It is somewhat remarkable that the Challenger Expedition failed to obtain, with the 

 exception of Lingula anatina and one example of Megerlia sanguinea, any of those 

 brilliantly coloured species which abound in many localities ; biit to compensate for 

 this deficiency several remarkable new forms Avere dredged, such as Terebratula 

 uiyvillii and Terehratulina loyvillii, this last being the finest and largest species 

 of the sub-genus Terebratulina hitherto discovered, either in the recent or fossil 

 condition. 



' In Ms paper on Japanese Limjulxe in.tlie American Journal of Science and Arts, vol. xv., 1878, Professor E. 

 Morse observes that his studies of Lingula have hronglit out many points new to science. The discovery of auditory 

 capsules in the class of Brachiopoda is one of the most important. These organs he. determined in a species of Lingula, 

 and then- position and general appearance recall the auditory capsules as figured by Claparfede in certain tubicolous 

 annelids. He has also, cleared up many of the obscure points in regard to the circulation, and is prepared to maintain 

 the absence of anything like a pulsatory organ, the circulation being entii-ely due to ciliary action. Mr Morse also 

 described some of the habits of Lingula. While partially buried in the .sand the anterior border of the pallial 

 membranes contract in such a way as to leave three large oval openings, one in the centre and one on each side. The 

 bristles, which are quite long in this region of the- animal, arrange themselves in such a way as to continue these 

 openings into funnels, and entangle the mucus which escape from the animal. These funnels have firm walls, a 

 continual current is seen passing down the side funnels, and escapiLng by the central one. They bury themselves veiy 

 quickly in the sand, and the peduncle agglutinates a sand tube. They attach themselves by means of this tube to the 

 bottom of dishes in wliich they are confined. 



