Reibun
、。

These two have completely different patterns, but no differences can be observed in internal morphology, so they seem to be considered the same species.

Literal

This 2-[counter-つ] [topic-は] pattern [subj-が] completely different [copula-のだが], internal morphology [to-に] difference [subj-が] observed-not-able same [quotative-と] regarded-[progressive-ている] seems [polite-です].

模様が全然違う 'patterns are completely different' uses 全然 with negative sense despite the positive-form adjective — a colloquial shift increasingly common. 内部形態 'internal morphology' is a scientific compound. みなされている (passive of みなす 'regard as') marks established scientific consensus. ようです adds hedging — 'it appears that.'