Transactions of the Coecticut Academy of Arts and Sciences

Transactions of the Coecticut Academy of Arts and Sciences

By (author) 

List price: US$24.10

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks

Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 edition. Excerpt: ...generic character when the corresponding family character is not in evidence? Of the other six characters of the Family Attidffi enumerated above, characters the combination of which might have come to our help, not a single one can be recognized. Even in recent spiders the spiracle can be seen only with difficulty, the diurnal type of eyes is an expression of the internal structure and cannot be preserved, the clypeus, if properly preserved would appear only in a plane vertical to the surface of the specimen and the absence of the colulus is only a negative character. The claws could be seen under microscope if they were preserved, but although every spider has either two or three claws on each tarsus, none of the specimens in question show any trace of them. Similarly, although the specimens show well preserved hair and spines, there is no trace of scales. The evidence, such as there is, points therefore against the probability of Parattus belonging to the Family Attidae. But let us assume for the moment that Parattus is an Attid. The separation of Attidae into genera is based on the following characters: --1) Number and structure of teeth on the lower margin of chelicerae; 2) Size and shape of the entire eyegroup; 3) Relative position of the eyes of the second row; 4) Number of spines on the underside of the first tibia; 5) Number and distribution of other spines on legs; 6) Distance between the anterior coxae; 7) Shape and especially elevation of carapace; 8) Shape of underlip; and 9) Shape of sternum. Most of these structures are either poorly preserved or entirely indiscernible. If the family relationship were definite then indeed the genus would be sufficiently characterized by the proportion of the anterior eyes and we could..show more

Product details

  • Paperback | 126 pages
  • 189 x 246 x 7mm | 240g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236853865
  • 9781236853868