Invertebrate Zoology

A single female genital pore is present in the midventral line of 14^th segment.

The characteristic feature of the intestine between 26-35 segments is the presence of internal median fold of dorsal wall called typhlosole.

A pair of male genital pores are present on the ventro-lateral sides of the 18^th segment.

At the junction of midgut and hindgut another ring of 100-150 yellow coloured thin filamentous Malpighian tubules is present.

Integumentary nephridia, attached to the lining of the body wall of segment 3 to the last that open on the body surface.

The development of P. americana is paurometabolous, meaning there is development through nymphal stage.

Limulus (King crab) is a living fossil.

Yes, it is correct. It is the scientific name of cockroach.

The life history of insects usually exhibit metamorphosis.

Three pairs of legs are attached to thorax region of a cockroach.

The dorsal chamber of the haemocoel is the pericardial sinus which is connected to the heart and gives oxygenated blood.  

insects   The Malpighian tubule system is a type of excretory and osmoregulatory system found in some Uniramia (Insects and Myriapoda),

During its life cycle, the silkworm actively spins continuous silk filaments to form its protective cocoon while it is in the caterpillar or larval stage.

Insects have malpighian tubules for excretion 

Centipedes (class Chilopoda), cockroaches (class Insecta), and crabs (class Crustacea) are all arthropods, which are characterized by jointed appendages and a hard exoskeleton made of chitin. These two features are universal across all arthropod groups. Compound eyes and book lungs are not present in all arthropods.