96 



SCIENCE. 



[Vol. I., No. 4. 



logical society of France, he has named it 

 Titanophasma Faj'oli. The interest attaching 

 to this remarkable creature, which has not be- 

 fore been figured, and to another somewhat 

 smaller species published by him five years 

 since under the name of Protophasma Du- 

 'masii, is twofold. First : scarcely any group of 

 Orthoptera is so specialized as the Phasmida, 

 or walking-sticks ; and one would naturally 

 look upon these bizarre creatures as the last 

 term in a long series of forms in a special line 

 of development. Thej^ had never been found 

 fossil, excepting in one or two fragments in 

 amber, when suddenl3'the upper coal-measures 

 of Commentry revealed a considerable number 

 of forms, of which M. Brongniart has only 

 described two. He points out, that the}- diflfer 

 from modern tj'pes in certain features, such as 

 the relative length of the parts of the thorax 

 and legs ; but their connection with living 

 Phasmida is unmistakable. Second : the hind 

 wings are of a type verj^ diflferent from those 

 of living Phasmida, and accord closely, as 

 pointed out in mj' paper on The early types 

 of insects, with those of a whole group of 

 detached wings found in carboniferous beds 

 in Europe and America (Dictjoneura, Paolia, 

 Haplophlebium) . These have always been 

 looked upon as Neuroptera. It can hardly 

 be doubted that these wings belong to this 

 early t3-pe of walking-sticks, — a probability, 

 we may add, strengthened by unpublished 

 material in our possession. Here we have 

 clear evidence of the presence, in early times, 

 of synthetic types of marked character. As 

 M. Brongniart informs me that he has now 

 over five hundred and fiftj' specimens of arthro- 

 pod remains from Commentrj' alone, and as 

 our own Mazon-Creek beds have doubtless 

 j'ielded as manj-, we may look for many new 

 revelations concerning tlie earlj' insect fauna 

 of our globe. I am already acquainted with 

 half a dozen or more species of Dictyoneura 

 and allied genera from our American coal- 

 fields, notablj- from Pennsylvania. The fig- 

 ures we give are from M. Brongniart's sketches, 

 reduced lineally one-half. The body is that 

 of the original specimen of Titanophasma de- 

 scribed in the Comptes rendus of Dec. 11. 

 The wing, his latest discovery, and not j-et 

 described, has merely been mentioned by M. 

 Brongniart, in the bulletin of the entomologi- 

 cal societj' of France : it was found detached in 

 the same beds, and is conjectured by him, 

 not witliout reason, to belong to the same 

 or a closely allied species. Of Protophasma, 

 specimens have been found with the wings 

 attached to tiie body. Samuel H. Scudder. 



ANATOMY AND HISTOLOGY OF 

 POL YOPHTHALMUS. 



This interesting genus, which was first discovered 

 by Dujardin in 1839, and more fully described by 

 Quatrefages in 1850, is the subject of a fine inono- 

 gfapli by E. Meyer in the Archiv fiir mikroskopische 

 anatomie, xxi. 769. The transparent worm is 15-18 

 ram. long; lias twenty-eight bristle-bearing segments, 

 followed by eight smooth, very small ones, none of 

 which are marked externally. The bristles form two 

 rows on each side. Most remarkable are the eyes; 

 •of which there are three on the head, and several 

 pairs on the body. In P. pictus, the species investi- 

 gated by Meyer, there are twelve such pairs, on as 

 many segments. The external cuticula is of nearly 

 uniform thickness, except over the sensory organs, 

 where it is thinned out; but the hypoderrais varies 

 considerably, and is composed of narrow cylinder 

 cells and relatively large unicellular glands, which 

 last have granular contents, an oval nucleus, and a 

 cross-shaped opening through the cuticula for the 

 duct. The external coat of annular muscles is very 

 imperfectly developed. The remaining muscle^ i-e- 

 semble those ot other annelids. The bristles arise 

 from the bottom of four pockets in each segment; 

 the pockets (hurxae) are invaginations of both the 

 hypodermis and cuticula; but the hypoderm cells are 

 cubical, and not cylindrical as over the rest of the 

 body. The brain is kept in place by a set of threads 

 of muscular and connective tissue, which run from 

 various points of the body-wall to the cerebral en- 

 velopes. A detailed description of the nervous sys- 

 tem is given. The ventral cord is nearly uniform, 

 and has no distinct ganglionic swellings. It lies 

 close against the skin, which directly underneath it 

 is reduced to a thick cuticula with a mati'ix of flat 

 cells, which pass suddenly on either side into the 

 layer of hypodermal cylinder cells. There are two 

 pairs of peripheral nerves in every segment. The 

 sensory organs are numerous and interesting. The 

 organs of touch are the cephalic and anal papillae. 

 The former is a small elevation of the integument of 

 the forehead, covered with a delicate cuticula and 

 thin hypodermis, and receiving a number of nerve 

 filaments. The nine anal papillae ai'e similar in 

 structure, but project more. There are also the so- 

 called lateral organs, a pair in each bristle-bearing 

 segment, which are probably homologous with the 

 seitenorgane discovered by Eisig in the C'apitellidae. 

 They lie between the two bristle pockets of each seg- 

 ment, and have the form of hemispherical projec- 

 tions, probably covered in life with free sensory hairs 

 arising from the modified hypodermal cells, which 

 rest upon a peripheral ganglion, from which they are 

 separated by a thin membrane; the membrane is 

 pierced by the cells to establish their connection with 

 the ganglion. There are beaker-shaped organs, hav- 

 ing evident resemblance with those ot fishes and the 

 Capitellidae, but present only in a single cephalic 

 pair. There is also a pair of ciliated pits of horse- 

 shoe shape on the oral segment. These pits are in 

 structure quite complicated; and their bottom has 

 hair-bearing sensory cells, which are greatly elon- 

 gated, have rod-like nticlei, and rest upon a ganglionic 

 layer, to which runs a large special nerve. There Is 

 an evident histological similarity between the ciliated 

 pits, the beaker-shaped organs, and the lateral organs. 

 The lateral eyes are of two sizes, those upon the eighth 

 to the fifteenth segments, both inclusive, being nearly 

 twice as large as the four other paii'S : they all lie close 

 against the''integument, the overlying cuticula and 

 hypodermis being both very much thinned. The 



