Deepak:

Your image on left reminds me of some unarmored dinoflagellate resembling Akashiwo sp., but it's just a guess, not sure.

Best

Syed

Thanks Dr. Syed!

pretty clueless on them but then, you have given the lead..

Best

Deepak

Dear Dr. Deepak,

Agreed with Dr. Syed that it is a dinoflagellate. It could be one of the  reproductive stages of the  genera like  Glenodenium or Gymnodinium. Further exploration is required to confirm its identity.

Hope the paper given below will be of some help.

Towards an Ecological Understanding of Dinoflagellate Cyst Functions,Isabel Bravo and Rosa Isabel Figueroa, Microorganisms 2014, 2, 11-32; doi:10.3390/microorganisms2010011 

Good luck

Dear Dr. Jackson,

thank you for the information and link

Best regards

Deepak

All of these images look like larval invertebrates, especially the two images on the right which look like echinoderm larvae.

Thank you Dr Cammie,

will check it out

Best regards

Deepak

The organiusms on the right side are diatoms similar to Odontella, Biddulphia, Triceratium, please look into Hustedt (1930) : Die Kieselalgen. in Rabenhorst' Kryptogamenflora - I do not have this volume at my hanbd in the moiment.

The organisms at the left have no character which should affiliate them to dinoflagellates, may be an invertebrate larvae as already suggested.

Thank you Dr. Malte for your information ..

Best regards

Deepak