Possible Clues:

• Centipede, e.g
• Hour saved by spinner entering a shaft, spider perhaps
• It's a hard case or hard top, possibly
• Animal with a segmented body
• Creature with hard top, or otherwise
• Non-university man joins old school as worker, perhaps
• Invertebrate with jointed appendages
• Spider or insect, e.g.
• Such as a crustacean or spider
• Hinge's foremost in construction of trap-door spider, for instance