In which one of the following the genus name, its two characters and its phylum are incorrectly matched ?

Options

A. `{:("Genus name ","Two characters",),("a) Pila ","Body Segmented"/"Mouth with radula","Mollusca"):}`
B. `{:("Genus name ","Two characters",),("b) Asterias ","Spiny Skinned"/"Water vascular system","Echinoermata"):}`
C. `{:("Genus name ","Two characters",),("c) Sycon ","Pore bearing"/"Canal system","Porifera"):}`
D. `{:("Genus name ","Two characters",),("d) Periplaneta","Jointed appendages"/"Chitinous exoskeleton","Arthropoda"):}`

Answer

To solve the question regarding the incorrect matching of genus name, its characters, and its phylum, we can follow these steps:

### Step 1: Identify the Options
We need to analyze the options provided in the question. The options typically consist of a genus name, two characteristics, and a phylum name.

### Step 2: Analyze Each Option
We will evaluate each option to determine if the genus name, its characteristics, and its phylum are correctly matched.

1. **Option A: Periplaneta (Cockroach)**
- Characteristics: Jointed appendages, exoskeleton made of chitin.
- Phylum: Arthropoda.
- **Analysis**: This is a correct match. Cockroaches belong to Arthropoda and have jointed appendages and an exoskeleton.

2. **Option B: Cyclops (Water Flea)**
- Characteristics: Asymmetrical body, canal system.
- Phylum: Porifera.
- **Analysis**: This is incorrect. Cyclops belongs to the phylum Arthropoda, not Porifera. The canal system is a characteristic of sponges (Porifera), not Cyclops.

3. **Option C: Echinodermata (Starfish)**
- Characteristics: Water vascular system, marine organisms.
- Phylum: Echinodermata.
- **Analysis**: This is a correct match. Starfish are indeed echinoderms with a water vascular system.

4. **Option D: Gastropoda (Snail)**
- Characteristics: Unsegmented body, calcareous shell.
- Phylum: Mollusca.
- **Analysis**: This is a correct match. Snails belong to Mollusca and have an unsegmented body and a calcareous shell.

### Step 3: Identify the Incorrect Match
From our analysis, we see that Option B is the only one that is incorrectly matched. Cyclops is not a member of Porifera but rather belongs to the phylum Arthropoda.

### Conclusion
The incorrect match is **Option B: Cyclops (Water Flea) - Asymmetrical body, canal system - Phylum Porifera**.

### Final Answer
**The answer is Option B.**

---